Hello
If you just wanted to morph the head you have to select whatever polygons you want to morph and detach them from your original - the morph modifier really does have to have equal verts - so you have to detach two heads and set up all the morphs you want. Later on the stack add an editable poly over the morph and weld the two pieces back together. When you drop back down to your morph it works just fine.
However not sure why you wouldn't just morph the entire thing still attached to the body unless you were having stack issues. When you are all done your stack should look like this - editable poly, morpher, edit poly, then skin or physique.
If its just a matter of not wanting to be able to see the body there are hide polygon tools in your editable poly roll down morpher works just fine if they are hidden.
Its really wierd to get used to Max after Maya or Maya after Max - later things work out because both programs have strengths. Think of the stack like Mayas history if its not there it doesn't work.