Yes you can. I had the same scenario. The programming of the buttons is done through the Mouse Software. I had an Optical Trackball 5 Button Mouse from Microsoft. I purchased it to be able to program the buttons that Inv would not let me assign a short cut key to. This was Version 8. I have been out of the solid modelers for about a year now.
Alan M. Etzkorn
Project Develpment Engineer
Wabash National Corp.