Ubuntu 10.0.4.1 Lucida 64bit Vbox Network Configuration

We got a virtual Ubuntu Server with one fix IP Adress. In this machine we have a vBox windows2003 server. Our application must run in the win2003 server and need complete internet functionality. We need you to configure the network of that system, so we can access on ubuntu via vnc, and on win2003 via RemoteDesktop. All Ports must be used by windows2003 server except the port for vnc so we have an access on ubuntu. Also we need an description of your work so we can configure it our self in case we need to setup everthing from beginning. I guess for someone with linux experience No Proplem!