Something

$irc->registerActionhandler(SMARTIRC_TYPE_CHANNEL, '^[!@]test', $test, 'test');

class test {

    function test(&$irc, &$data) {

        $irc->message($data->type, $data->channel, "Hello! My name is ".$irc->nick);
        $irc->message($data->type, $data->channel, "Pleased to meet you, ".$data->nick);

    }

}