What type of virtual server are you using? A hosted VPS, Virtualising in XEN, VirtualBox, VMWare? I am going to assume for the sake of helpign you that it is a VPS, where there is no way to gain "console" access. In this case you can install xorg, vnc, and whatever window maanger you want. then you will want to ensure that the VNC port is open and start a VNC server. Or better yet tunnel your VNC through an SSH session. You would generally start the vnc server session with a command like
Code:
vncserver -geometry 1024x768 -depth 15
it will prompt for a password and then tell you what screen the server is one, likely :1 whihch is also the same as network port 5901.