you are right, when you 1st create yr morphs in Zbrush you save the morphs as .obj but once you enter poser6 you must import the .obj as a morph target and then you apply the morphs to the charcter and you render your scene.
But if you want to save those morphs you must to create a .cr2 that contain the morphs so that you can use them in other 3d softwares such as SAZ Studio.
That what i want to know how