Formatting a number

[TheBigB]

Hi,

I'd just like to know how number formatting goes in PHP.
I need to format in the way: 1 = 0001, 23 = 0023 etc.
I know there is a method involving printf, but that doesn't quite do the job.
The thing is that I need it stored in a variable instead of printing it.

Thanks,

[penagate]

$myvar = sprintf('%04d', $mynum);