Unless I'm misunderstanding you, the only choices you have are the ones listed, e.g. here
. Exactly what effects it causes on the other person's computer (notifications, new window, etc.) will be controlled by his
client. The showing up in the channel is different - but I think all the commands such as '/msg' and '/notice' that you will find are private, so won't show up in the channel.
In summary: If I've understood you correctly, I don't think you can - it will depend what software (both IRC client and things like libnotify) your friend has on their computer.