Official comment
Sorry David, but that's not an option at this time. I'm not sure if it could be done as you outline, but we envision Requirements.cc evolving into more of a stand-alone tool - like CaseComplete is today - rather than an even further and more featured integration between the two.
There are other options available right now, though. CaseComplete's version control system is Subversion-based, meaning that you can integrate pretty seamlessly with Subversion servers outside of your client networks. There are some free hosted solutions out there, as well as paid options. More details are here:
Thanks for the suggestion, David; we'll keep it in mind as we plot the course for Reqs.cc and CC into the future!