molding an object in the shape of another object im trying to create a daz custom face morph. i have a custom face from another model i want to apply it on the genesis 8 fem model in blender. but i cant cut and past it straight away because i need to preserve original model vertices count otherwise it wont import into daz as morph. so im thinking perhaps there is a tool that molds an object in the shape of other object without changing the vertices or polygons count. i already extracted the custom face mesh. now all thats left is to mold the original genesis model face in its shape. something similar to how clay molds work in real life.
If I understand your question correctly,you are looking for the Shrinkwrap-Modifier. Add the modifier to the model you want to change and choose your "desired face" as the target. For further reading consult the manual. 

However there is no way to get more detail than your polycount allows. That means the Shrinkwrap-Modifier might produce artifacts if the polygon-density of your model is far less than that of your target.