It will still display it and do the local host lookup because when mIRC connects it sends your localhost info to the server. Here's a sample of the raw event:
-> irc.bigpond.com USER Blah "glass.nsw.iserv.com.au" "irc.bigpond.com" :BlahThat is what my script sends. All IRC programmes do much the same thing. Without that the server won't accept your connection.
*Watchdog taps Khaled on the shoulder... It would be a nice touch if mIRC could haltdef these status window events...