Topic: Change to Title Case but between parentheses only

I want to change the case of all first letters to upper case. BUT in the (...) parentheses ONLY.

I have to learn because i don't know Siren Renamer (It's not that heavy).txt

I have to learn because i don't know Siren Renamer (It's Not That Heavy).txt

String modifier : "[ ]"
It will be split into an array of substrings following the specified separator characters.

in combination with
Case modifiers
Case modifiers are specified just after the '%' of the variable :
u >> all characters upper-case
l >> all characters lower-case
U >> first character of each word upper-case, the others lower-case.
     The words are separated by the characters specified in
     "Preferences/New name computation/Word separator characters".
L >> first character upper-case, the rest lower-case

%b[1,"("] \(%Ub[2,"("].%e

%b[1, "("]    >> will split the string at the "(" sign and give the first part back. We use this just unchanged.
" \("             >> add an blank and the split delimiter again. (It seems the String modifier drop trailing spaces)
%Ub[2,"("]  >> give me part 2 of the split file name. The "U" means here: change to Title Case
.%e             >> add the original extension.

Tested with Siren File Renamer v3.00 rc1 build 900 ( don't ask ;-) Times flies ... and, this is a old test pc)