Is anyone familiar with this great tutorial: http://gnomonology.com/group/31
Is there a way to do this on only part of a model?
Simply hide or mask completely the parts of your model you don’t wish to sculpt.
But the image that I would use needs to effect part of the model…not the whole thing.
Lets say I have a shell texture map and I want the shell map to just effect the shoulder of a bipedal creature. If I apply the map it would cover the entire character. I’m reduced to creating an entire blank texture and adding the shell map onto it and hoping that I’ve positioned it right in Photoshop.
There must be a way to isolate the texture map where I want then using the method only in that area?
You can polypaint with a texture and then use Intensity masking, though you need to disable UVs so that the texture doesn’t appear on the whole model. Here is a method that you may find suitable for your purpose:
http://www.zbrush.info/docs/index.php/Tutorial:ZProject_and_Adjusting_Photo_Reference
If you want to create texture maps you will need to restore the UVs and then use the Tool>Texture>Col>Txr option.
use Projection Master or Zapplink to position your texture.
(Zapplink will work better because in Projection Master you can only move and scale your texture,you can’t rotate it (only by 90degres angles).
Perfect! Thanks Guys 
The tutorial says it uses the Image Plane 3 plugin but the link is dead???