Just an update..... It works perfectly.
When I finished it, I had a problem that I drove me nuts for 8 hours but I found the addition of two diodes solved it. The entire change to the drape motor is easily done if you are handy with a soldering iron and a pair of cutters, and have about twenty minutes to spare.
This design will allow the drapes to be opened and closed, or partially closed, using your existing transmitters or programs, but will automatically close the drapes on a command from the powerflash no matter what position there in.
I will get the photos and "how to" together in a few days time and will upload it to a new post separate from this one.
Dick