I have a router that I use here on campus that allows me to be online on my computer and on Xbox Live.

The only way I can get the Xbox to recognize the school's network is to hook the Xbox directly to the ethernet port in the wall.

I'm pretty sure that the Xbox recognizes the router as the LAN I want, but I want to be able to keep everything connected and connect to the school's network, to play others in different rooms.

Is there a certain way I'd need to set up my router, or is this possible?

I'm a bit sketchy here, but have you attempted to configure your Xbox to pick up the connection, and if you did, did it fail? The router doesn't seem to be the problem, as long as it works fine with your computer, your Xbox should pick up the connection OK.

Have you got the ports open for the xbox's IP? Xbox 360's are anal about routers afaik.

Mine seems to be fine with our router. Then again, we operate an access control list and, even though DHCP is turned on, every device always gets the same IP.