One way is that you can have a master INJ script which calls several other INJ morphs (which each have one head morph).  Then you hide the other INJs in a subfolder in the character's pose folder.  It's ugly, but it's a solution.  Probably not what you are looking for though.

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.)