Setting up a VPN in Windows 2003

I have a network with Windows 2003 standard behind a linksys BEFVP41 (10-user office) with DSL. The router has a static IP on it and the local network uses 192.168.x.x range. I want to set up the server with RAS for about four clients to remotely access the server.

The server has 2 adapters, but I only want to use one with the RAS, as the router is providing “routing.” During the install of RAS in 2003, it insists that you use both adapters. I’ve scoured Microsoft and TechPro, etc., etc., but can’t find how to set up RAS with one adapter, using the router as the router portion. I know I will need to forward the ports on the Linksys.

Anyone have any experience with this? I’m at my wit’s end.
Thanks! sblades