Capitalizing sentence with commas inside parentheses

[ohrenkino]

Doesn't this problem resemble a little this one:

Move "Featuring" from Artist to Title

You have mixed something into the $regexp() function, which might be not allowed ... or does not work per se, ... which is here ... the function $caps2(). You may do what you want in a following second step ... Action "Format value" Tag-Field : ARTIST Formatstring: $regexp(%ARTIST%,'^(.+\sfeat.\s)(.*)$','$1')$regexp($regexp(%ARTIST%,'^(.+\sfeat.\s)(.*)$','$2'),'\b\w*\b','\u$0') ... or ... Formatstring: $regexp(%ARTIST%,'^(.+\sfeat.\s)(.*)$','$1')$caps2($regexp(%ARTIST%,'^(.+\sfeat.\s)(.…

You describe a pattern with 3 parts but only the third gets treated.
I do not think that you can "replace" that but you have "Format value" the field again with a separate string function for each part that you then have to isolate with a regular expression each.
If you use $caps() you may have to define the characters that determine the word separator.
I tried the following:
$caps3($regexp('5:01AM (The Pros and Cons of Hitch Hiking, Pt. 10)','(.+) (\(.)(.*,.*\))',$1 $2$3),'(')
and got
5:01am (The pros and cons of hitch hiking, pt. 10)