Thank you for your answer. I managed to make a button which opens the external DVD player skin. Power DVD also opens but something goes wrong. I don't know what exactly is going wrong but no DVD gets played and the mouse cursor keeps jumping into the upper left corner. I can only exit by pressing CTRL, ALT DEL. Any clue what causes this?
I'm also integrating Destinator 7 into the UF skin. I managed to start Destinator 7 from the 'main menu', but when Destinator 7 opens it does not open in the window in which it supposed to be opened, but shifted a bit to the lower right corner. Strange thing is that Destinator 6 opens correctly (not shifted).