Configuring IIS 4.0

I have DSL through an ISP. Our router is using NAT. Our ISP takes care of our DNS. We use WINS and DHCP. Our Proxy Server has been given the IP 192.168.0.2 (this is what the outside world sees). This is not a real IP. Our “real” IP is 64.182.38.114 but is not bound to the NIC of the Proxy Server.
Here’s my question: I created a web site on IIS 4.0 which is on NT 4.0. The rest of the world can see my site but we cannot see it from inside the network. “page cannot be found” is what we get. My ISP is no help and I’m an IIS novice. Can anyone please help? Thanks,