Code:
on *:INPUT:#:{
  if (!$istok(/ $readini($mircini, text, commandchar), $left($1, 1), 32)) && (!$ctrlenter) && (!$inpaste) {
    var %text
    var %i = $0
    while (%i) {
      var %text = $+($left($($+($,%i),2),1),$replacexcs($mid($($+($,%i),2),2), [color:blue]k,kj, K,Kj, l,lj, L,Lj[/color] )) %text
      dec %i
    }
    msg $chan %text
    haltdef
  }
}


See the blue section , add what ever ones you need in there.

NB: you said k does not become kj, so i assumed the first letter of a word doesnt get done.