In the example from perlfaq:

$padded = sprintf("%${pad_len}s", $text);
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So where it says that you may use an integer in place of $pad_len, it means that it would be written as:

$padded = sprintf("%04d", $text);
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Cheers,
Darren :)

Update: Actually, after re-reading this I realised that the original code snippet I gave you was incorrect. I've corrected it.

Also, it's worth pointing out that $pad_length in the above examples is a little misleading, as it actually refers to the total length of the resultant string, rather than the length of the padding. The best way to demonstrate this is by example:

#!/usr/bin/perl -w
use strict;

my $string1 = "12345";      # 5 character string
my $string2 = "1234567890"; # 10 character string

my $pad_len = 10;

my $padded1 = sprintf("%${pad_len}s", $string1);
my $padded2 = sprintf("%${pad_len}s", $string2);

print "|$padded1|\n|$padded2|\n";
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|     12345|
|1234567890|
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Note that the 2nd string isn't padded at all, because the length of the string is already >= than $pad_len.

Update: blah - you're working with numbers, not strings. Disregard the previous update, and I'll crawl back into my box :)