ECHO OFF
for %%p in ("%1" "%2") do if %%p=="" goto wrong
for %%f in (a d) do replace %1*.* %2 /%%f/p
GOTO end
:wrong
ECHO.
ECHO Format for the command is
ECHO.
ECHO UPDATE source-disk: dest-disk:
ECHO as in  UPDATE a: c:
ECHO.
ECHO Copies files to the backup disk that are either not
ECHO already present or are later versions of those already
ECHO there. Asks for confirmation before copying each file.
ECHO Current directories are used unless otherwise specified.
ECHO.
:end