I think you could use sprintf like : 
$result = sprintf("%07s", $name);

[download]
"%07d", since your new file names would always 7 characters long.

Update : too late :(

Update : As blazar said, "%07d" is wrong, I updated it to "%07s", which seems to work better : sorry for the mistake.

In reply to Re: Optimize file renaming. by Tomtom
in thread Optimize file renaming. by omega_monk

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