How about sys("dv 2>/some/errorfile")?
I'm amazed DoubleVision is still available. I'd be more amazed if it could tap into a WindX connection and do anything meaningful with it, unless it's become a graphical tool. They used to just map character mode devices, depending on the server side to just be sending out ansi or similar terminal escape sequences. WindX has its own protocol for transmission (just think about those FIN packets mentioned earlier).
What about using web meeting software, like teamviewer or gotomeeting?