How do I assign a Razer DeathAdder Black Edition key to Mission Control?

I have purchased a Razer DeathAdder Black Edition mouse, and the latest Mac driver I can find for it is 1.00. The possible assignments for the side buttons don't seem to have Mission Control buttons available for them (they only have various Expose keys available)

Is there a hack around this? Or do I just have to do without? Or exchange for a different Razer mouse with a more developed Mac driver? Or just use the Mac driver for a different Razer mouse?

I'm not familiar with the particulars of your mouse and the associated drives, it probably hasn't been updated for Lion yet, so I wouldn't expect any Mission Control options built in at the moment. The simplest way would be to see if you can have the button assigned to a particular keypress, which you can then assign to Mission Control in the Keyboard Prefs.

If that doesn't work, try Steermouse, it's a 3rd party mouse driver that works with almost every extra mouse you'll find, and gives you some additional features and flexibility.

I've got my Razer Naga configured to work with Mission Control.

I've used the Razer drivers to set up the button I want to use to trigger Mission Control to trigger Mouse Button 3 (you can bind any button to this):

Then, I've set up System Preferences to use Mouse Button 3 to trigger Mission Control:

That's been working fine for me; no extra software required.