This got me further curious....... I run a
Rapoo 7100P . it has two extra programable buttons on the side of the mouse, I ran the set up software and surprise, surprise it will allow one button to be + and the other to be - and the game will respond.......not quite the wheel but a step in the right direction. Also........it will allow the scroll wheel to be set up for up to be + and down to be - which the game will respond to ( the problem with that is when I use the scroll wheel in the forums instead of going up and down this happens-----+++++++----------+++++++++++-------------+

)
So with the right mouse you may be able to set up the game to respond to the scroll wheel but that is only becasue you are telling it to be the + or - key