Someone

ALIAS 

reg {
  if ($1 == !true!) { /say TRUE }
  elseif ($1 == !false!) { /say FALSE }
  else {
    %reg.nick = $1
    whois %reg.nick
  }
}


Regcheck.mrc 

RAW 307:*:{
  if ($2 == %reg.nick) {
    reg !true!
  }
  else reg !false!
  haltdef
}