You could try the Sketch Designer inside of Poser itself. Do a render, and theneither paste the render to the background, or import it as a background, and choose a Sketch Render preset. There are some presets for sale at DAZ that may get the look if the standard ones don't do it.

http://www.daz3d.com/shop.php?op=itemdetails&item=2422

Well, that's if you want to do it in Poser. It would probably be easier to do it in a paint program though.

 

Here is a pic of me imported as a background in Poser 6, and sketch rendered. Who would have thought you could use Poser as an image manipulator? :)