I have this working one way now. The server from behind the pfSense box can map drives, copy files, remote desktop to a server behind the Fortigate. So if that server initiaites the connection everything works. However, if the server from behind the FortiGate trys to initiate a connection it does not work.
By looking at a tracert, it appears that once the packet gets to the Fortigate, it does not know where to go. I just get "Request timed out".
I think it is a Fortigate routing issue and I am going to keep fiddling with it. ???
-John