Surface manipulation through control points.

Hello,

I'm able to see the control points by using the surface>analysis>surface points

I've also extracted the surface normal of my surface and gave it a comparative angle

against the z-axis so that the value returned tells me where the normal is more horizontal than vertical.

What I want to do is move the control point (manipulate the surface) by moving the points who subsurface normals are more horizontal by their corresponding factor. 

Instead what I get are a bunch of surface points that dont seem to move the surface at all.

If I use those point to create a surface the points are no longer in order and the surface is wrecked (that is if it doesn't crash the program).

Clearly, I'm doing something wrong.   Can anyone point me in the right direction or link to a sample script that manipulates a surface by individual points (as opposed to the offset command which affects all of them the same )