custom generated document – filename of referenced graphic + figure caption

It's been a long week already, and my brain has turned to mush – I thought I had once managed to set up this sort of report, but just at the moment I can't remember how. The context is a .book with many referenced graphics; each graphic has a caption, which I can identify by specifying a paragraph style.

Any reminders on how to achieve this would be welcome, as would (I suppose!) confirmation that I'm just fantasising :-}