#! /usr/bin/perl -ni
BEGIN {
    @ARGV = my $file = "hai";
    die "File '$file' doesn't exist!" unless -e $file;
}

print
    if s/HAI WORLD Times ([0-9]+).*/
          "\t\t<exML LOLZ = \"" . unpack(\'a1\', $1) . "\" />"
        /eg;

##</code><code>##

$replaceString = sub {
    "\t\t<exML LOLZ = \"" . unpack(\'a1\', $1) . "\" />"
};
# time passes

    $array[$elementIdx++] = $replaceString->();