Remote Message on Mirc

I am in trouble. Please help me.

My uncle who out of country and we are not confirm where he is right know and my uncle?s son is expired here that?s why we want to give him a message on Mirc. Because I know he almost daily chat on Manila, USA, Pakistan and Japan Channel. But I am not confirm about his nickname.

Therefore I want to give a message (i.e. UNCLE YOUR ELDEST SON ARSHAD IS EXPIRE PLEASE CONTACT US) in a query window repeatedly to all the users of these channel at the same time. I mean after every three times a new query window open and give same message to all users.

Please help me.