Easy-peasy, just change the first step above to this instead...
In online.php, find this:
if ($user['U_Status'] == "Administrator") {
$piece['0'] = "";
preg_match("/-ANON-(.*)/",$Username,$piece);
$Username = $piece['1'];
}
and change to this:
if (($user['U_Status'] == "Moderator") || ($user['U_Status'] == "Administrator") ) {
$piece['0'] = "";
preg_match("/-ANON-(.*)/",$Username,$piece);
$Username = $piece['1'];
$hostname = gethostbyaddr($piece['1']);
$anonrow[$x]['hostname'] = $hostname;
}