Thanks,rfeenie!
I have since taken another tack on this problem. On the assumption that I may have more than one CDrom, or indeed dvd or whatever, I am developing a little app which will find a target file on any drive, and set the system on that drive. this basicly is done by going to each drive in turn, searching the root of that drive for a target filename, and exiting. Currently, it is at the 'it works' stage, but needs cleaning up & error trapping. At that point, I will ensure you have a copy.
The scenario will be, boot from boot CD with cd rom drivers then use the little app to get onto the cd, batch file then to do the business.
Johncob. [sig][/sig]