Why not just convert all of your Cyrillic characters with $utfencode identifier? Like this:

Code:
//echo $utfencode(CyrillicCharactershere)


Once entered, your mirc will output ANSI result.

Finally to test, in your mirc remote, put this code in and your bot will recognize these Cyrillic characters:

Code:
on *:TEXT:*:#: {
  if (<EncodedResultHere> isin $1-) {
    msg $chan $nick says $v1
  }
}