Thanx for the info guys, i finally got it going in XP with a fair bit of experimentation...
The driver for the later model of my touchscreen actually installed on XP, and after a bit of trial and error with the baud rate setting, it sprung into life! Under WinXP! The calibration also works.
I wish I'd done this sooner, but I've had a lot of things that have flat-out refused to work under XP since there was no driver, I should count myself lucky that it's working.
I should have my set up done by the 20th or 27th if I don't hit on any more problems.