Add \Rx to reltool on flexpendant

Hi!

I want to rotate my tool using reltool. 
How do I add the argument \Rx:=45 to the reltool argument on the flexpendant.
I cant get it to work. If i write the rapid it in Robotstudio it work fine and end up on the virtual flexpendant. But how to add it on a real flexpendant?