Robocopy, copy none existing files to destination

This is how you copy none existing files to a destination with Robocopy, including subdirectories

   robocopy /xc /xn /xo /s <source> <target>

and if you want to exclude some directories too, use this:

  robocopy /xc /xn /xo /s <source> <target> /xd $flac 'this dir too' forgetmetoo