Making Airport appear as a computer
Have you tried talking to your campus' Network Administrators? Plead your case! If they ask why, hold up your iPad. You are never going to be running a cable to that thing with the intention of using it on a network. Only power and maybe headphones!

Working with them might let you use your wireless with their recommended settings. Maybe bring the Express with you and let them configure it in the manner they want. Maybe they would prefer you NAT yourself, maybe they would prefer you to Bridge the connections.