I believe he wants it to change anything he types in. So what Collective said is correct but you'll need a little extra code for it to translate everything you say.

Try this (place this code in your Remote scripts):
Code:
on 1:INPUT:*:{
  say $replacecs($1-,a,A,c,C)
  halt
}


That way anything you type in will automatically have the a and c translated into A and C respectively.