Possible to use Win2000 computer as a router over dialup?

I have a rather complex situation here that is hard to describe, but I'll try:

I have a Dreamcast game system with a built-in 56k modem. There are several games still online for it, but I would like to use my broadband connection so that I'm not tying up the phone line while I play PSO.

Here's what I'm trying to get at:

The Dreamcast is directly connected to the Win2000 computer via a phone cable (null-modem cable?). Repeat: the two devices' modems are directly connected; I don't have money for a second line so I can't just route the call through the actual phone system. The Win2000 machine will have a NIC as well, to share the broadband connection with the Dreamcast "dialing-in" to the machine. (I do know of a way to make Win2000 answer the modem when it's not ringing, so that won't be a problem) The hard part is this: in order to play games, I'll need NAT capability. Win2000 has this built-in, but I need to know whether or not it will be able to use port forwarding to do NAT with a machine connecting through a dial-up adapter.

It seems like I can use either RAS for the dial-in or ICS to do the address translation, what I need to know is if I can use both. I would like to use Win2000's built-in NAT capabilities, rather than plunking out $$$ for third-party crap.

well, that is complicated...and i figured you meant a simple proxy

you MAY be abel to assign the modem a static ip then use a free proxy (or windows ics) to forward stuff to and from the modem, but i dont know how the dreamcast would like not gettign a dialtone. Look for a phone emulation program maybe?

good luck man.