Thanks for the help, it does look as though a 3rd party app is the best way to do this. I tried the one you posted at http://www.actionscripts.org/forums/....php3?p=579584
, but if I recall correctly, it was asking for permission to use it, or it just didn't work with more recent versions of Flash (or I was being dumb and not being able to get it to work somehow).
I also tried Adobe Air, but clearly I didn't read it properly, I was trying to do it with AS2, which will be why nothing was happening!
I've ended up doing it in C++, it doesn't look as pretty, but it works and I still have some hair left to pull out in future. Thanks anyway.