currently i have a router (DHCP configured in it) and a switch. i like to add a windows server 2003 into this. this is how i like, keep DHCP setting in router then connect 1 cable from router to 1st NIC of server and then connect a another cable from Server's 2nd NIC to switch. all other pc are connected to switch. so, my question is how to configure the server as a domain controller while keeping the DHCP setting of router unchanged.

I would suggest you take a simpler approach. Ask youself this question: how is dhcp from the router going to go thru the server to reach the pcs on the switch? Why would you give up ms server dhcp dynamically updating ms dns? Are you planning on running a proxy server or internet monitoring/limiting application? If not there is no reason to pursue this setup. Instead router [no dhcp] connects to switch. All pcs/servers connected to the switch.