I couldn't start EL from within an RDP session, but I was able to use the client if I had left it open on my home PC. After some googleing I found the answer, and would like to share it with you.
Steps:
1. open notepad(++)
2. copy paste the script
3. save the file as startel.bat in your EL folder (C:\Program Files (x86)\Eternal Lands)
4. Start cmd,exe (dos) as administrator
5. browse to EL folder
6. type: qwinsta.exe
7. look for the line: rdp-tcp and remember the ID
8. start startel.bat <id>
9. follow the instructions
script:
@echo off
if [%1]==[] goto DISCONTINUE
echo.
echo Remote Desktop will be temporarily disconnected . . . please reconnect after a few seconds.
echo.
pause
@echo on
tscon.exe %1 /v /dest:console
@echo off
echo.
echo Starting MyProgram.exe . . .
@echo on
start el.exe
@echo off
echo.
pause
goto FINISH
:DISCONTINUE
echo.
echo Please specify Session ID. (Session ID can be found with qwinsta.exe command.)
echo.
:FINISH