(feat.) before ( Character in title

I'm using an action that for sure gives me (feat. xxx) like

Be (D-Malice Afro Expression) (feat. Kid Fonque, DJ Whisky)

so case sensitive for the (feat. ) part shouldn't be a problem if thats what you mean?
I've tried this action after

Field: TITLE
Format String: $regexp(%TITLE%,'^(.+?)\s((.+?))\s((feat.\s.+?))$','$1 $3 $2')

but won't change
Be (D-Malice Afro Expression) (feat. Kid Fonque, DJ Whisky)
to
Be (feat. Kid Fonque, DJ Whisky) (D-Malice Afro Expression)

here is the thread