Mixed case after a word

I have titles with feat. george benson).mp3 and I want to change to feat. George Benson.mp3

How can I do that?

Thanks in advance

are you talking about titles or filenames?
do you want to remove the parenthesis?

to change all words but a few selected to Normal Case, do the following:

Action: Format Value
Field: TITLE
Formatstring: $replace($caps($regexp($lower(%title%),\b(feat|featuring|vs)\b,@@@$1)),@@@,)

this is for the TITLE field, for filename use _FILENAME
I have selected the word feat|featuring|vs to stay in lower case, you can add as many as you want.

Sorry I did'nt explain well:

The TITLE is

Minnesota shuffle feat. george benson).mp3

and I want to change to

Minnesota shuffle feat. George Benson.mp3

Only change the part after "feat."

Thanks in advance

What a mess. You don't want to change Minnesota shuffle into Minesota Shuffle as it would be correct format for titles, but you care about the artist name?
And where comes that closing parenthesis without opening from???
And you want a TITLE tag field ending with .mp3???

Are you sure?

here you go anyway:

or if the parenthesis is not always there:

Thank you very much. Was perfect

I don't want title with mp3. and I like the title like this.

Another question please?

How to filter only the files with "feat."?

%title% HAS feat.
%_filename% HAS feat.