New help setting up a proxy and a few other things...

[cocokrisp]

I want to set up a proxy server on my PC (running XP Prof) that can be accessed from PCs outside my network. This PC is connected to a d-link router (along with a few other PCs) and they all share the same internet IP which is assigned to the router. First of all, how do I set up a proxy that can be accessed from an outside PC? Second of all, how do I configure my router so that people outside the network can access my proxy on this PC even though I only have 1 internet IP? Thank you very much for any assistance you can provide!