Well, I can think of two things.  One is you render them seperately and then shop the hair onto the body in postwork.

The other idea and this is just a guess because I've never used that feature is gather (check the stickies on the top of the forum for links to it).  If you could use a dark enough color or a negitive one, that might work.  Or you could use a lot of tiny, dark point based lights with a very close max distance, but that could be a ton of work depending on the hair you chose.

I'd suggest doing it in post work.  To make it easier, do it against a green or blue background and delete the links to the texture on facial regions and make them the same color as your background.

WARK!

Thus Spoketh Winterclaw: a blog about a Winterclaw who speaks from time to time.

 

(using Poser Pro 2014 SR3, on 64 bit Win 7, poser units are inches.)