Capo chords on piano grand staff

How can I attach capo guitar chords to a piano grand staff? This is common in song books, with a full piano part and guitar chords for a guitarist to vamp along. But the capo option is disabled for piano because it’s not a fretted instrument. Can I fool Dorico into thinking it is fretted? Moving it to the fretted instrument family doesn’t do it. Or is there some other way?