iTunes won't play from write-protected drive

I have an external hard drive with a back-up of my music collection plugged into my computer at work. Our office security system renders any external drive plugged into a network computer write-only to prevent removal of data.

iTunes will not play any songs off the hard drive. Most won't add to the library at all; for some reason, I am able to add some songs to the library, but all metadata other than the song title is gone, and the file will not play. I'm assuming this is because the drive is write-protected. Is there any way around this? (I am able to copy the files onto my computer's hard drive, and they'll add to the library and play just fine from that directory, but I don't have a lot of space on the computer and don't want to move the songs there if I can avoid it.)