You can make custom identifiers with aliases, e.g.
alias hello {
join #channelthatwontexist
return hi
}
//echo -a $helloWhen you call an alias this way all the commands in it are performed (just as if you had typed /hello).
From the mIRC helpfile:
$scidIf you specify a property which is an identifier, it returns the value of that identifier for that connection. This also works for custom identifiers.
So typing
//echo -a $scid($cid).hello will also call the hello alias and perform all the commands in it.