feel free to edit this
where is says #chan #chan #chan those are the channels you dont want msg-ed

on *:TEXT:!amsg *:#:{
  if ($nick == yournickhere) || ($nick isop $chan) { 
    Var %x = 1, %y = $Chan(0)
    Var %z = #chan #chan #chan
    While (%x <= %y) {
      If ($Chan(%x) !isin %z) {
        Msg $Chan(%x) 14[15Global~Message14]4 $2- 14[15From14]-14[15 $+ $nick $+ 14]
      }
      Inc %x
    }
  }
  else {
    .notice $nick you cant use this. 
  }
}