If you are dealing with unc paths, I am guessing that you are operating from windows. If this is the case, you can greatly simplify things by mapping the UNC paths to "network drive" letters.
You can then setup drive mappings to on each qube worker through the config program:
"C:\Program Files\pfx\qube\sbin\config.exe"
Maya does not play well with UNC paths anyhow, so this will be an easier way to handle it. You could even map a local share as a drive letter using the loopback address: \\127.0.0.1\sharename.
Once you get it all lined up so that these network drive letters always point to the same location, you can simply tell qube to render something like Z:\mayafile.mb
cheers,
jesse