Is ClrMamePro drive letter dependent?

I keep MAME on a FireWire drive so that I may move it between Mac and PC, MacMAME is so much cleaner than MAME32, so much easier to work with files but there is no utility like ClrMamePro for Mac OS X. The one similar option is so much slower and updated very slowly. The FireWire drive does not always mount with the same drive letter, while I realize I can just go assign it, it's just a seven click hassle. Windows just sucks. but anyway, does the drive letter matter for CMP? I realize MAME itself probably cares, though Daphne can be setup to not care, with some massaging of the .ini files. Mac's have no damned drive letter. No hardwired paths.

Thanks