Hi Craig,
Some flash apps will be happy to do web requests instead of dealing with the file system; you'll need to check with the app's docs/developer/source to find out if this is possible. If it is, then you'd simply point the flash app at a PHP page that outputs text.
If your flash app doesn't support this, it could be done through custom programming. Our consulting team could make a plugin for you which keeps text files updated when records are saved in CMS Builder. Please let me know if this is something you're interested in and we can get more details and a quote for you.
I hope this helps! Please let me know if you have any questions.
All the best,
Chris