So very glad you talked me out of Quitting = Very Happy Pinhead here!
For those peoples who have been following this adventure - Mike DA Spike - and his co-horts have solved my problems, all my tables that have a virtual DMD (with this fix) in Future Pinball will be able to add the DMD to their 3rd screen.
Thank-you so very much. I'll now try to write a .bat file for VPX and other tables to work with PINBALL X.
OBTW DMDext only works on tables that already have a DMD.