I know how to do this using a microsoft mouse and downloading intellimouse explorer drivers, you just change every button config there is.

 

However I am using the bluetooth dell keyboard/mouse and vista 64 so the dell bluetooth drivers dont work and im runing on standard windows stuff and the standard windows drivers dont let me change what each mouse button does, I like adding flip3d to one of my mouse buttons however I dont know how to do this with this mouse. microsoft intellimouse drivers dont work with my dell mouse.