@Taerar: You can do it this way:

on @!*:JOIN:#channel: {
  var %x = $isupper($left($regsubex($nick,/\W+/g,$null),1))
  mode $chan $iif(!%x,-v $nick,+v $nick)
}
on !@*:NICK: {
  var %x = $isupper($left($regsubex($newnick,/\W+/g,$null),1))
  if ($newnick ison #channel) && (%x) { mode #channel $iif(%x,+v $newnick) }
  else { mode #channel -v $newnick } 
}

Change #channel to your actual channel name