The songs were as below:
Artist: Various - Singles
Title: DJ Antoine - Welcome To St. Tropez
I copied the %title% to some bullshit tag like %lyricist% as a backup.
On replace with regular expression I converted %title% to $2 on expression (.) - (.)
Then I copied %lyricist% to %artist%.
Then I did the same thing on replace with regular expression but with $1.
You could transfer the data without the fussing about with a "bullshit tag" by using actions of the type "Import tag field".
You start with %artist% and the mask
%albumartist% - %album%
and continue with the same type of action only this time for %title%:
%artist% - %title%