How to configure mouse commands?

I've been editing keys.ini for keyboard commands, but it does not contain any mouse commands. Where are the mouse commands stored?

Currently the mouse scroll wheel zooms in or out (I think move_forward and move_backward). I want to change this to spin_around_cw and spin_around_ccw (I have a trackball with a scroll "ring".

I'm having problems with my logitech trackball, it worked before using SL on another pc. Now...I can't click on anything in game! It works perfect on my desktop or any other applications. Just can't click on any items in SL world! I've checked the settings...chgd them to slow...then fast...tried all different settings and still nothing. I don't know where other settings may be changed in SL, but maybe you have a suggestion on this for me?
Thanks very much!