Can’t access a Belkin router past a Windows 2003 Server

I have a Windows 2003 server acting as the router, domain, dns and dhcp server. I cannot access my Belkin ADSL router thats on the other side of my server. When I type the IP address of the Belkin into explorer it says page cannot be displayed. I imagine thats because the IP address isn’t on the local side of the network and that the external DNSs the server uses obviously doesn’t know it. The server doesn’t know to look on the external side network. Its probably a dumb question but I can’t seem to find an answer.