Anonymous Monk,
Because I am lacking in creativity, I will give you the first thing (and probably not the best thing) that came to mind). 
#!/usr/bin/perl -w
use strict;
my $number = '4744760012394122';

if ($number =~ /^(\d{4})(\d{4})(\d{4})(\d{4})$/) {
    $number = "$1 $2 $3 $4";
}
else {
    print "Unable to convert $number\n";
}

[download]
I hope that wasn't your real credit card number.

Cheers - L~R

In reply to Re: Simple formatting question for credit card number by Limbic~Region
in thread Simple formatting question for credit card number by Anonymous Monk

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