Using relative path but exclude /cygdrive/

I have a Ubuntu rsync server setup and I'm trying to backup a number of windows machines. I have /rsync/servername/ setup for each server. In there, I want the paths preserved from the server but using the -R or --relative in Deltacopy creates /cygdrive/C/.....
Instead of backing up c:\path\to\files\ showing up on the server as /rsync/servername/C/path/to/files/ it's /rsync/servername/cygdrive/C/path/to/files/

Is there a way to accomplish this without having cygdrive included in the relative path?