|You say WAN but you also say VPN so I'm going to assume your remote site is connected via VPN.|
Have you tried using Remote Desktop Connection?
First, on the target PC set it to allow remote connections. Then all you should need is the IP of the target PC. Run RDC from the PC you wish to connect from, enter the IP of the target PC and you should be able to connect.
I am of course assuming your VPN endpoints use the same subnet.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.