Add " ) " at the end of certain TITLE(s)

I have made a mistake while changing my songtitles.

I'm trying tot re-organize my iPod Classic music collection (about 110GB). I'm changing the TAGS with Mp3Tag v.2.72
and everything is going well, except for one problem:

I've changed a lot of my song files with "...Feat/ft. ARTIST..." to (Feat. ARTIST

What I want:

TITLE: Songtitle (Feat. ARTIST1 & ARTIST2)

I have some titles:

TITLE: Songtitle (Feat. ARTIST1 & ARTIST2 without the ")" and some with the ")"

Long story short:

I want to add the ")" at the end of certain titles which contain the phrase "(Feat.". without the ")" at the end.

Please help me out!

Bart, Netherlands

I would filter for these files:
%title% HAS "(" AND NOT %title% HAS ")"
%title% HAS "(feat" AND NOT %title% HAS ")"

Then select the resulting files and create an action of the type
Format value for TITLE
Format string: %title%)

Great! I wasn't aware of the HAS and AND NOT function, I'll be using that a lot!