$replace isn;t so great for this job...
//echo -a $replace(this is an example,is,isn't)
Code:
on ^*:text:*:#:{
  var %1- = $1-
  while $istok(%1-,wonderful,32) { %1- = $reptok(%1-,wonderful,,schitterend,1,32) }
  echo -mbflirt # $+(<,$nick,>) %1-
  haltdef
}

You can keep adding words to replace in like manner
  • while $istok(%1-,wonderful,32) { %1- = $reptok(%1-,wonderful,,schitterend,1,32) }
    while $istok(%1-,lol,32) { %1- = $reptok(%1-,lol,Laughing out loud,1,32) }
    and so on...