<PAGE>

                                                                Exhibit 4.(a).30

                      AMENDMENT TO STOCK PURCHASE AGREEMENT

          THIS AMENDMENT, dated as of April 17, 2006 (this "Amendment"), to the
Stock Purchase Agreement dated as of April 12, 2006 (the "Agreement"), by and
among ROSS SYSTEMS, INC., a company organized and existing under the laws of
Delaware (the "Purchaser"); C360 SOLUTIONS INCORPORATED, a company organized and
existing under the laws of Georgia (the "Company"); and MR. JOHN GRAVELY having
an address of 1441 Woodland Hills Dr Atlanta GA 30324, MR. JEREMIE DESAUTELS
having an address of 2444 Oak Grove Heights Decatur, GA 30033, MR. JEFFREY L.
LONGORIA having an address of 14361 Club Circle Alpharetta, GA 30004, MR. SANIN
SARACEVIC having an address of 587 Virginia Avenue #1009 Atlanta, GA 30306, MS.
LISA PATRICK having an address of 4664 Brunning Court Atlanta, GA 30338, and MR.
ARVIND RAMAN having an address of 6203 Madison Dr Atlanta, GA 30346
(collectively, the "Sellers"). Capitalized terms used but not defined herein
have the meanings assigned to such terms in the Agreement.

          Pursuant to the terms of the Agreement and in accordance with Section
12.05 thereof, the parties hereto agree to amend the Agreement as follows:

          SECTION 1 AMENDMENT TO SECTION 2.02 (D)(IV). Section 2.02 (d)(iv) of
the Agreement is amended by deleting the subsection in its entirety and
replacing such subsection with the following:

          "(iv) In the event that the difference between [Actual Current Assets
               - Actual Current Liabilities] - [Closing Current Assets - Closing
               Current Liabilities] (such difference the "Difference Amount") is
               greater than $70,000, then the True Up Amount shall equal:"

               Difference Amount - $70,000

          SECTION 2 AMENDMENT TO SECTION 2.02 (E)(I). Section 2.02 (e)(i) of the
Agreement is amended by deleting the subsection in its entirety and replacing
such subsection with the following:

          "(i) a first, second, third, fourth, fifth, sixth, seventh and eighth
               installment of 50,000 shares of CDC Corporation Stock for each
               installment shall be payable respectively on the following dates:
               Within 10 Business Days of the Closing ("First Stock
               Installment"), on the three month anniversary of Closing ("Second
               Stock Installment"), on the six month anniversary of Closing
               ("Third Stock Installment"), on the nine month anniversary of
               Closing ("Fourth Stock Installment"), on the twelve month
               anniversary of Closing ("Fifth Stock Installment"), on the
               fifteen month anniversary of Closing ("Sixth Stock Installment"),
               on the eighteen month anniversary of Closing ("Seventh Stock
               Installment") and on the twenty-one month anniversary of Closing
               ("Eighth Stock Installment"). The payment of the First Stock
               Installment, the Second Stock Installment, the Third Stock
               Installment, the Fourth Stock Installment, the Fifth Stock
               Installment, the Sixth Stock Installment, the Seventh Stock
               Installment and the Eighth Stock Installment shall not be
               conditioned upon the employment, continued employment or
               achievement of any performance objectives of any of the Sellers
               with respect to the Employment Agreements"

          SECTION 3 AMENDMENT TO SECTION 2.03. Section 2.03(b) of the Agreement
is amended by deleting the last paragraph of the section in its entirety and
replacing such paragraph with the following:

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          "The payment of the First Cash Installment at Closing and the First
          Stock Installment within 10 Business Days of Closing shall be the last
          action performed at Closing and shall be made promptly after receipt
          by the Purchaser of the Equity Interest, and are conditioned upon: (a)
          the execution of the other Transaction Documents; and (b) each of the
          other conditions precedent set out in this Section 2 and Section 7."

          SECTION 4 TAX ELECTION. The Sellers and the Company consents to enter
into an IRC section 338(h)(10) election in connection with the sale and purchase
of the Equity Interest and agree to do everything reasonably necessary to give
effect to election and to use all reasonable endeavours to cause relevant third
parties to do likewise

          SECTION 5 FULL FORCE AND EFFECT. Except as expressly amended hereby,
the Agreement shall continue in full force and effect in accordance with the
provisions thereof on the date hereof.

          SECTION 6 GOVERNING LAW. This Amendment shall be governed by and
construed in accordance with the laws of the State of New York without giving
effect to the conflicts of laws principles thereof

          SECTION 7 COUNTERPARTS. This Amendment may be executed and delivered
(including by facsimile transmission) in one or more counterparts, and by the
different parties hereto in separate counterparts, each of which when executed
shall be deemed to be an original but all of which taken together shall
constitute one and the same instrument.


                                       2

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          IN WITNESS WHEREOF, the Sellers, the Purchaser and the Company have
caused this Amendment to be executed as of the date first written above by their
respective officers thereunto duly authorized.

ROSS SYSTEMS, INC.


By:
    ------------------------------------
Name:
      ----------------------------------
Title:
       ---------------------------------


C360 SOLUTIONS INCORPORATED


By:
    ------------------------------------
Name:
      ----------------------------------
Title:
       ---------------------------------


JOHN GRAVELY


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JEREMIE DESAUTELS


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JEFFREY L. LONGORIA


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SANIN SARACEVIC


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LISA PATRICK


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ARVIND RAMAN


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