Well got the armrest and panel off. It was held on by no less than four big screws and was able to see what has happened. Lights and lock/ window plates snapped out. A small plastic fitting for a ball in the middle has cracked, this moves in a slider so the window goes up and down. Now I understand why my father always said "Don't slam the doors". Obviously, not engineered by the Germans. Just for kicks I will go to a Caddy dealer and see if they have it. I'm certain if I had it done at a dealer it would cost a small fortune.
This should be interesting trying to find a replacement part. I'm sure if I go to Cadillac it will be part of a larger mechanism. For the time being, I will cut a board to length and wedge under the glass in the closed position hoping this will not be the permanent fix.
Thanks for all the suggestions. If anyone sees a part like this let me know.
Thanks again for all the comments and encouragement.