/e
c:\
file1
file2
file3
file4
d:\
file1
file2
file3
file10
(just file 4 will be copied to D: and file 10 will be left as it is)
^that's with /e
if you have /MIR
it would remove file 10 (from D ) and copy file 4
have a quick read here http://www.ss64.com/nt/robocopy.html
thanks Bledd, you have been a star on this mate