Code:
on *:CTCPREPLY:version*: {
  if ($regex($2-,/^mIRC v[5.91]|[6.1]|[6.11]|[6.12] Khaled Mardam-Bey$/)) { 
    do stuff 
  }
}

DALnet #Helpdesk
I hear and I forget. I see and I remember. I do and I understand. -Confucius