yes, too much oil can and will damage the transmission.
to measure the transmission fluid level, you first need to get a transmission fluid dipstick from Audi and then follow a decidated procedure to measure fluid level. The ATF needs to be at 80 degrees (not less and not more, best achieved by driving ~10 km after a cold start), the car has to be absolutely level, the engine must be running and all gears should have been selected (with the shifter) for a few seconds prior to measurement. Audi has replaced the ATF dipstick with a dummy plug in 1989 to prevent owners from measuring the ATF level themselves, as there have been lots of cases of DIY overfilling and subsequently damaging the transmission. Since I have a manual and am no expert in this, I hope that others will take the lead from here. You can also have this done at Audi - at least they SHOULD know how to do this :-(