Delete words up to a space dash space

Support
1

I have a title made up of the name of the composer, a space, a dash, a space and the title of the work
I would like to delete the composer the space the dash and the space to find only the title of the work

2

Try an action of the type "Guess value" (import tag fields)
Source: %title%
Target: %composer% - %title%
which saves the first part in COMPOSER

or if you really want to delete it:
Source: %title%
Target: %dummy% - %title%