Now you have a controller for joint3 with a value range of 0 to 10. We have to do the same for each joint so be patient. Select the locator and test it to see if it works. By giving values to grab from 0 to 10 the finger should move. Next thing is to do the same but to joint4 and then joint5 and so forth.
Lets do a few more.
Select joint4 and press Load Driven. Then select the Grab attribute like in this image and the rotate XYZ of joint4 and press key. Select locator and give Grab a value of 10. Select joint4 and rotate it to its maximum and press Key. Now if you change the value of Grab, the finger will move but only the two joints we key.