MacDrive is not going to change the video.
If these files are on a HFS volume from a Mac system then you need MacDrive to mount the disk on a Windows system. Best $50 I spent in a long time.
Having solved that minor issue then you could face a much bigger issue. I don't know if Vegas can read those QT files anyway. You may need Raylight to convert them. Hopefully someone whose dealt with that issue before can give you a more exact answer or maybe a visit to the Raylight site will clue you in or you could try searching here.