🚀 go-pugleaf

      >When I followed instruction, I got stuck by the provided formats which
      only allow page number, auto number, text of the whole paragraph, etc.,
      but not a word.<<

Unfortunately, I think you're stuck. You can insert a cross-reference marker directly by highlighting the word and choosing Special>Marker, but AFAIK there's still no cross-reference *format* that returns only the marker text. My initial thought was that you might be about to insert markers, generate a list of markers formatted so that each of the marked words would appear as a separate paragraph, and then cross-reference the list... but then it occurred to me that the cross-reference markers in the list would go away every time you regenerated. 

I hope someone cleverer than me will have a better answer for you.... 

-Bill