Have you got a "Printer Cable" for your CC? If so, it's a null modem cable and you can use a terminal/file transfer package.

If you have a USB <-> Mac serial adapter for your other Macs it wouldn't be difficult at all to do your file transfers. If you've got a PC laying around a DIN 8 <-> DB-25 cable isn't all that hard to come by, and a straight thru cable can be easily adapted to a null modem config.