Yes that works EXCEPT it creates the shadows on a white background. Since I will be compositing I prefer to have this on a transparent background like you get when you render to images (PNG).  I can do it this way but then I will be forced into chromakeying out the white background. Is there a way to have the shadows ONLY without the background?  My settings are Render Over:current BG shader with the Shadows Only box checked. tks.

Windows 10 - Poser Pro 2012 - 64Bit - 24GB RAM - 4 x 3.40 GHZ processor