Assuming they are just standard switches, presumably you could get a cheap USB gamepad with lots of buttons, rip out the insides and hook wires from the gamepad switches to the Audi wheel. This would require you to solder, of course.
Then use some software like joystick 2 mouse (http://www.imgpresents.com/joy2mse/j2m.htm) to map the switches to keyboard combinations for whatever application / frontend you use.
Am I right? I'm certain this has been done before, well at least thats what I plan to do with my passat