Rdesktop - From Linux to Windows in VPN

Hi Gurus,

I have a Linux server in a Private Network which i connect through a VPN client. This Linux server is the only server from which we have access to all other servers(Windows & Linux) in the Private Network(hitherto referred as PN).

Now i want to RDP into one of the Windows boxes in the PN. I have installed rdeskop in the Linux machine and have started an "X" server(Xming) in my desktop(windows).
I have exported the DISPLAY variable in Linux server to my desktop.

However i am not able to RDP into the Windows box.While troubleshooting this issue,i noticed that when i log into the PN,the IP Address gets NAT-ed. I guess this causes the export of DISPLAY variable to fail.

I am in a fix now as to how to proceed. Please throw some light.

Thanks
HG

Be sure access to Xserver in windows and XServer is listening which port ?
for exa is might like this

# export DISPLAY=yourwindows:0.0