Classification Rule Builder: Regex - replace with upper case

Hi all,

I'm currently trying to convert one of the search results in the Adobe Analytics Classification Rule Builder to upper case.

Simple Regex: ^([a-z])([a-z]+)

The match works and gets back as $1, $2. usually I would expect the behavior to work as $U1, U$1 or \u$1 to change the next character to upper case but it doesn't work. Any ideas or solutions on this functionality?

Thanks!

Best,

Konstantin