Hi.  I'm new so this might not be of any help, but here goes...

What I did when I imported poser people into Carrara, was I selected the toon pro option under render.  There should be a little arrow thing next to where it says photorealistic.  I clicked on that and selected toon pro.  Then I fiddled with the render settings, with full raytrace on, and out comes a toon render.  I don't know if that is the same as cell shaded, but I seem to get a decent render by turning off draw lines and up the pixel depth to 16 where I can.  It seems to convert the poser model textures into  toon textures.

I hope this helps, if not, sorry, I am new.

David