The displacementpallet (Mode is on to get a displ.map in stead of just a bumpmap) generated an alpha; This alpha I exported **with flipV and flipH checked**:

-Then in Poser 7 I imported the LoRes headobject with Flip Normals checked:
-I prepared the Rendersettings for displacement in FireFly:
-Finally I imported the exported alpha as a displacementmap, I checked "displacement" and set the depth of displacement to 1,5; 
-Then finally I rendered the picture.
As you can see there is - at last Halleluja! - something that resembles the ZBrush hires head. 

But there is much difference, that I cannot account for nor can I change that one.
It would be very nice if someone could help me some further it making it somewhat better.