Please understand that I mean no malice
No one has answered the question that is currently posted by the originator. I don't have the answer either as I am curretnly looking to find where I saw the correct hotkey, last fall.
There is a hotkey that will take a user from his "fullscreen" Microsoft session via RDESKTOP back to his desktop.
I just don't happen to recall what it was and I'm looking (I know it works because I used it).