Karibou, at Rdna, has just posted a script she kindly made to do this in response to my also asking there .
It was her RenderStudio tute that prompted this query on my part and now she has added links to the script in the RenderStudio forum where the tute is !

" Try and be nice to people, avoid eating fat, read a good book every now and then, get some walking in, and try and live together in peace and harmony with people of all creeds and nations."
-Monty Python