After all, you may be right. Using Powder X-ray Diffraction . But you already probably possess a lot of the knowledge described in that book, and may skip some parts. If not, however, have a look at the CCP14 Web page on this subject . It is essential to be able to convert powder data to any format that you may need at any time.
Some software are for peak fitting, or more, but can open and save in various formats.
Not that simple, but this may be the kind of thing that you may have frequently to do in powder diffraction jobs. You may find more details on some of the conversion software at the CCP14 page on that topic . Convert or Powder by Nita Dragoe. WinFIT by Stefan Krumm. ConvX by Mark Bowden.