Im sure thers a way to do this but i dont know where to begin...

Ive brought home the powerbook from the office to prep it for a ,eeting tomorrow. Unfotunately i dont have a router here at home. So i wanted to share my internet connection and ave acces to the PB via APF/SMB and ARD. However when you share a connection it turns the connected computer into a router essentially and there is no GUI for advanced setup to use port forwarding or configure NAT. Im sure theres a back door way by manually edditing some config files in the shell but im not sure what files i need to find. So how do i go about it? I realize its probably quite involved so im not asking for a step-by-step... i i jsut new what file si was looking for i could probably adpapt other intructions focused on servers/routers from the net somewhere.