how to configure a display for the OC FMC

Hi,

Today I tried to configure my OC FMC V3 to work with the PMDG NGX.
The FMC display is working but I can't for the life of me figure out how to get the PMDG FMC display to show on the OC FMC.
I've tried undocking and resizing but this leaves me with a window frame which I can't make disappear. Besides, the frame also shows on the edge of my main display which is kind of horrible.
So is there a way to separate the PMDG CDU display from it's surrounding hardware so that it could be more easily resized ? Although I still think you'll be able to see the window frame.
If somebody knows how to do this please help me.

thanks

martin