I think the way to go with this would be to:
1. Try to create pxtone voices as close to the organya instruments as possible
2. Figure out the pxtone file formats
3. Convert the .orgs to .pttunes
4. Write a wrapper for the pxtone dll
5. Use the wrapper to play the .pttunes.
Steps 1, 2, and 4 can...
I wrote some Python code which, AFAIK, correctly read the .org files. If you want, you can make use of it (the midi conversion code doesn't really work, though).
You can check it out at http://devan.infogami.com