To replace an existing script, you will need to copy the user id from your old script to the new one. Look for a line
$userid=987654321;
in the new script. Simply replace the number with the user id from your old script and then follow the usual installation instructions.
At last: a port to Windows! Many thanks to Michael Baltrush.
This version provides a work-around for Unix systems that limit the length of the command line. If you have problems submitting a large number of files try this script.
The current standard script.