XP mode error writing file path not found

I'm trying to run a DOS program (Locoscript 2.51) in XP mode on a W7 Ultimate virtual PC. This doesn't run - with a message 'error writing file(xxxx) path not found'.

Program works perfectly in native XP (on a different machine) and the file is in the same place on both.

Any ideas for a fix?

Thanks.

I posted the same query on the MS technet forum and was advised to use DODBox!!

So...

The program works perfectly on a native XP Pro machine.

The program does not run on a Virtual PC/XP mode under W7 Ult.

The best Microsoft suggestion is that I use a 3rd party program? And presumably uninstall virtual pc/xpmode.

Surely there must be some way to fix this?