[NTG-context] Overlay caption placement

[Dave]

>  I have a few pdf figures that I'm including in a large report that are
>  essentially full page (portrait) diagrams.  However, they each have
>  blank space in the lower right corner and I was thinking that it would
>  be nice to put the caption in this spot.  Is there a way to overlay a
>  caption on top of a floating figure?  Ideally, I'd like to be able to
>  provide an x,y offset location for these captions in cm.  Is there
>  something I'm missing in setupcaption?
>
>  Cheers,
>  Dave
>

Anyone have ideas on doing this?