Remote Display Tool: You can use the remote Display Tool V3. See also here.
Unfortunately MS removed a lot of features from WEC 7 to WEC 2013 (see also here). One of those is also the RDP support. One other option would be to go for WEC 7 instead of WEC 2013, we you could still use this feature.
Thanks for the post.
I tried the efonVNC for WEC2013 and it works fine. It actually was more responsive than Remote Display. It also use a lot less CPU time than remote display.