I guess you need shadows on other parts, right? Or it would be easier to turn off shadows at the light. I searched freestuff and couldn't find a script for this. Perhaps Ockham or someone equally skilled at Python could do it?

FREEBIES! | My Gallery | My Store | My FB | Tumblr |
You just can't put the words "Poserites" and "happy" in the same sentence - didn't you know that? LaurieA
  Using Poser since 2002. Currently at Version 11.1 - Win 10.