NAT- How do I set it up???

My NAT server is a win 2k adv server, domain controller(192.168.0.1) which is connected to the net by dialup modem. My second machine is a win 2k pro client. I would like to continue using DHCP AND DNS on my Domain controller if possible. My ISP allocates random IP’s. Can’t seem to get it to work. -sounds like an exam question 🙂 I have tried running through everything in the resource kit and I am obviously missing something.