To copy from usb to usb would be
wbfs copy gameid
e.g.
wbfs K copy H RBMPGT
I think you can only copy one game at a though, somebody please correct me if I'm wrong.
Don't know if anybody is interested but the cli command to rip straight from backup DVD to wbfs using this version of wbfs.exe is
wbfs add \\.\:
so for e.g.
wbfs k add \\.\d:
where k is the wbfs drive and d is the dvd writer
hope AlexDP can incorporate this into WBFS Manager