Counting tracks by each artist

I want an action that appends to %artist% the quantity of the selectedtracks that are by that artist. I can't see a way to do this. Anyone know one?

Just an idea, not verified yet.
Use the tracknumber assistent, set the option which may tell you about the amount of selected tracks. Then use an action to extract the number from the TRACK field.

DD.20090907.0915.CEST

Use the tracknumber assistent

The Autonumbering Wizard?

set the option which may tell you about the amount of selected tracks.
Then use an action to extract the number from the TRACK field.

Thanks D, but that doesn't provide quantity of the selected tracks that are by each artist.

Anyone?