I agree completely that it would be nice. I built a similar feature into my XRef Wizard plugin for structured documents, where you can search for all cross-references in a book that point to any particular element. It produces a hyperlinked report for each one. I use it frequently.
The methodology for unstructured crossreferences would be identical. Probably the most difficult part would be the reporting aspect; ie, creating a report, displaying results in a pod, or whatever. The process of searching through a book for matching cross-references would require relatively little code.
Are you asking whether it can be done? Or are you asking for someone to do it for you? The answer to the first is an easy "yes", the other not as much 
Russ