Ok I have made som progress here....
Using VNC Viewer for Win32 4.0 by realvnc I am able to open a session, aftering entering the password, that shows a grey desktop with nothing on it (twm). Left clicking on the desktop I am able to select xterm and start up an xterm session.
My question is- I would like to start a session so that I get the GUI login screen (like I am at the console), in the same manner that Windows Remote Desktop Connection presents you with the login screen of the Windows server you are connecting to.
It seems that with vnc all connections are done under one user.