Thanks Mdmackillop

I tried your code and it works, but there are two issues that I still need to overcome, but still don't know how:

a) it opens the pictures with my default web browser (IE) instead of Photo Viewer (I specifically want Photo Viewer)

b) it needs to an Excel App to run - I want to run it directly from a .NET vbexpress form. (I can do it using a hidden excel app, but would prefer to be a bit more elegant than that.)

Could you advise further?

Thanks for your help so far

Pieka