Delete " - " at end of field

In the process of renaming lots of mp3. Got lots of actions going on. For some reason in some fields I am left with a hyphen - at the end of the field. So I need an action that will globally remove - if the - is the last letter of the field.
Hope you can understand this problem.

Create an action of the type "Replace with regular expression".
(select the field - I wouldn't do it globally but specifically for artist, album, title)
Search string: (.*)-$
Replace string: $1

It could be that you end up with a trailing blank - then modify the search string like this:
Search string: (.*) -$