Hi,
I'm sorry to hear you're experiencing issues with it. Which version of ForestPack you're using? While there was a known issue in FP8, it was resolved in FP9 and the following command in the latest beta version (FP 9.0.8b) should work just fine:
Forest_pro.ForestPack.exportData "c:\\tmp\\test.xml" "index geomID geomName finalTM"
I hope this helps.
Best regards,