By default, the game binds Wheel up to Next weapon and Wheel down to Previous weapon. I want to reverse that, so I click "Bind" and scroll the wheel in the relevant direction. But the game doesn't record wheel up or wheel down; instead it records just "Mouse Wheel", and only one command can have this binding. So now I'm stuck with Next weapon bound to "Mouse Wheel" and Previous weapon bound to nothing at all.

Is there any way to get the game to bind Wheel Up and Wheel Down instead of just "Mouse Wheel"? If there's no in-game method, is there a config file I can edit some place?