Connecting to xbox live in uni halls, help!

I'm living at Paragon in Brentford (University of west london) and having massive trouble connecting to xbox live. to use the internet we need to log in with a username and password every time (the halls of residence use key com). Me and my friend have figured that when we try to connect to xbox live, obviously the console can't display the login page so we can't connect to the internet.

Is there a way around this? We've set up a wireless router in our flat (all the other rooms use ethernet) and have tried connecting to the internet on the laptop through the wireless router, then connecting the xbox to the laptop via ethernet cable but still getting nothing.