I'm amusing you want the artist and title is there given fields e.g. Artist: Billy Idol Title: Cradle Of Love (1990)
First use this filter [F3] to filter out all the titles which only contain one '-' in them so you don't mess up any files with two '-' e.g. 'Billy Idol - Cradle Of Love - (1990)
"TITLE" MATCHES"^[^-]+-[^-]+$"
Use to set up and action with the 'Guess Values' action.
Begin Action Group _Script Test#TEST
Action #1Actiontype 7: Import tag fields (guess values)Source format __: %title%Guessing pattern: %dummy% - %title%Action #2Actiontype 7: Import tag fields (guess values)Source format __: %artist%Guessing pattern: %artist% - %dummy%
End Action Group _Script Test#TEST (2 Actions)
Please see FAQ on how to go about creating actions.