How to Bridge two networks in windows 2003 server

In our office we are using one DHCP server and it is configure with Windows 2003 server. Our server has 2 nics on it. One is Connected in Network series of 200.200.200.100 and the other network is in the series of 192.168.0.5. Here the problem is that we have internet connection form one ISP is in the 192 series of N/W. I have to bridge these twe networks in this server. Please help me out how to bridge the two netwoks and these clients of server should access internet.