Code:
on 1:NOTIFY:{
if ($nick == [color:red]your friends nick[/color]) .msg  [color:red]your friends nick[/color] Hi there m8!
}

paste that in your remote "ALT + R in mirc", be shure to change the red parts to your friends nick.. and also be shure to have him added in your notify list.. if you want to add more nicks, then just copy the line
if ($nick == your friends nick) .msg your friends nick Hi there m8!
then put it below the first one and enter another nick to it..