Not that I can figure out. Of course a two finger tap opens the right click menu just like always. I don't see any other way. When I click the S Pen button I get the Note 5 air command menu.
There is one RDP app besides MS RDP which support S-pen, it's "aRDP: Secure RDP Client" available on google playstore for free. In my view, this app works far better than MS RDP