Proxy servers on Windows 2000

[prince1142003]

My computer class is trying to set up something, and we can't figure out how to do it.

Here's the scenario:

Our school network uses a proxy server, the IP of which we know. We also know the IP of the gateway. We've got a server up and running, attached to a router. We've just built an assortment of wireless PCs that all connect to the router. Now how do we set up the network so that the wireless PCs use the server as the gateway? And how do we authenticate the school network's proxy server on our Windows 2000 server?

Normally, you require a username and password to access the computer. Some older computers ask for the username and password when accessing the internet. Basically, the second scenario is what we want to set up on our wireless PCs. The server will act as a gateway, and users trying to get on the internet from the wireless PCs will be asked for their username and password, which will be authenticated on the school network. Any ideas on how to configure the router and the gateway server to do that?