convert filename to artist

Hello,I need your help.
here is the filename
086 Human League - Don't You Want Me.mp3

here is the function i use to convert filename to artist
$mid(%_filename_ext%,5,$strchr(%_filename_ext%,-))

here is the outcome i got
Human League - Don

How could I get "Human League" instead of "Human League - Don".

Sincerely yours
Chenmin

Use the converter menue Filename -> Tag or define an action of the type "Guess Values".

Convert String:
Format string: %dummy% %artist% - %dummy%

Action-Type: Guess values
Source format: %_filename%
Guessing pattern: %dummy% %artist% - %dummy%