Hmm, you will of course be breaking your agreement with the University by doing this and could get kicked off for doing so.
However, you would need something to act as a router as you say. This could be a router or could be a PC acting as a router - you need two network interfaces for this, the "outer" interface connects to the collage network, the "inner" interface (which could be Wi-Fi) is what your other devices connect to.
The router will translate all of the inner device addresses to the outer address (given to you by the university network).
There are impacts to consider. Nothing on the outside will be able to see the inner devices unless you configure Network Address Translation (NAT) in the router. Some services will not work with NAT but most do.
The other impact is that the traffic from your room is likely to be higher than average which may be detected by the network monitors and flagged. A clever monitor configuration would also be able to detect the apparently hidden inner devices using packet inspection. The only way to avoid that would be to run a "Virtual Private Network" (VPN) from the inner devices to somewhere outside the university network. There are public services that will do this but you will probably have to pay for them.
All told, you will never be sure that the university network monitors wont pick up your activities (well you might be sure if you get caught!!)