I don't think so, however sometimes Blood will think the click-in function of your mouse wheel is the third button on your mouse. (there used to be these mice that had a third button where the scroll wheel would be)
I think this only happens when you run it in DosBox though.
The mouse wheel click IS the third mouse button. The wheel up and down would have to be bound to some separate keys (respectively) using some program that does button mapping for the system. After that (or before if you are wierd) you would assign the proper key in Blood, and then it would work. Maybe I'll do that! (for weapon switching).
You know what bugs me? They got rid of leaning left and right in Blood. The key setup option for those commands was never removed.
-Slink loves you.