Something like this would do the trick:
REM Filename: sync-dirs.bat
REM generic robocopy backup script that DELETES (purge) files on the
REM Destination if they are also deleted on the Source! (i.e. sync/mirror).
%ROBOCOPY% %SRC% %DST% /MIR /R:10 /W:1 /ETA
Hope this helps..