LabVIEW has been cross platform since version 3 (partially in version 2.2 and 2.5). LV 6.1 was not around 5 years ago, so the Mac application is probably in an older version. Generally a 1 or 2 version update just requires recompiling. If your original program is in version 3 it might be more involved.
Try recompiling the program first. If that works you are done. If not, then you may need to do an intermediate upgrade. LV 3 -> LV 4 -> LV 5 -> LV6.
As for moving the files, try writing them onto a PC formatted floppy or ZIP disk from the Mac. The PC should then be able to read them. The Mac can read and write PC formatted disks but the PC cannot read Mac foramtted disks.
I have old versions of LV for Mac so I may be able to help if you need an inter
mediate upgrade.
Lynn