Format String - Remove Leading Characters

MP3Tag v3.03
I know taht when performing Filename - Tag the format string %title% will copy the Filename over to the Title, but how do I remove the leading characters of the Filename?
Example: 01 - Song.mp3 > Song.mp3

Try:
%dummy% - %title%
or
%track% - %title%

You could also have a look at the Documentation:

and the examples in First Steps: