Is there any way to add stars to the Library filter, or set a filter for different ratings?

[Brian Baker]

Currently, if I go to options, and set "Filter_1" to "Rated," and hit the corresponding key, then the filter gets set to ★

There seems to be no way to increment the filter-rating, or set the rating to anything other than "★"

Can I assign a filter with multiple stars to a button? Or barring that, add a star to the filter? I can't seem to make it work