How to play LAN across shared connection?

How to play LAN across shared connection?

I have three computers (1. one powerful one for gaming, 2. one weaker one that i let my friends play lan on, 3. and a laptop that cant run anything).

Computer 1 is downstairs in my basement hooked directly to the router.
Computer 3 is connected via a wirless adapter to the wirless router (its running xp)
Computer 2 is connected to computer 3 which has a shared connection to my router.

(Basicly im using my laptop as the wireless adapter for computer #2 upstairs so it can get internet access.)

My router has the address starting at 192.168.1.1, the computer that is upstairs connection is 192.168.0.1.

How do i connect to my downstairs computer that is hosting the lan server from the upstairs computer running across the shared connection?

Hope this was clear enough, ask for more info if you don't understand.


Thank you.