Something

on *:text:.amsg *:*: {
  if ($address($nick,2) isin %admin) {
    amsg $2- × $nick ×
  }
  else {
    .notice $nick you do not have permission to use this.
  }
}

alias addmin {
  if (!$ial($1)) {
    echo -a I don't know that user's address, please try again.
  }
  else {
    set %admin %admin $1 - $address($1-,2) : 
  }
}