Originally Posted By: starbucks_mafia
unfortunately there's no easy way to check for built-ins so you'd probably have to check against a hardcoded list of existing commands in your script.
It's possible to fetch mIRC's internal errors:
Code:
alias !msg {
  msg # $iif($1,$1-)
  return
  :error
  if (/msg: insufficient parameters isin $error) {
    echo 4 -a * The error $qt($v1) has been caught!
    reseterror
  }
}
/msg <message> will send a message to the channel. Without the message but the /msg command, it'll echo that the error has been caught in red.