Update.
I can use the bat file to have PinballX start dmdext. But it would close dmdext when I closed the table. So I would have to launch the bat file for every table I started. But that was a significant step thanx to scutters. With the help of another brilliant member on VPforums, wiesshund, I have dmdext starting and closing for every future pinball table I start. It`s not 100% successful yet, the odd table has a hissy fit when dmdext starts but I will iron out those problems later. My next step is to customise the dmd for each individual table.
So thankyou scutters for the help. 👍I really appreciate it.