Move the anchor points

Hi guys,
I have a problem moving my anchor points.
My code was created with Kangaroo2 and starting from a rectangle, I determine the surface and the mesh.
Finally, before using the solver, anchor the 4 end points.
but I would like to move those points inside my mesh to go back to the shape I need.
I am attaching the code (18.4 KB)

This definition seems a bit confused - you evaluate 16 points on a surface, but all but 6 of the points you’ve chosen are the same. You then select the closest vertex on the mesh to these points on the surface, but the mesh is very low density, so there are only 16 vertices to choose from.
Finally, if you’re moving all these internal points with anchors, the form isn’t really catenary any more.

Anyway, for anchor points, the P input lets you identify the point you want to move, and the T input is the target position you want it to go to.

thank you so much.
defining a thicker mesh can I have all 16 equal points?
Another question: how can I maintain a catenary shape if I’am forced to use the anchor?

Take a look at the attachment. (19.9 KB)