Create reference surface from measurement points (Creo3)

Hello,

I'd like to know how I can create a flat (reference) surface from results of a 3D measurement.

The 3D measurement file consists out of x, y z points measured from a certain flat surface of a product.

I want to make a flat reference surface which I can compare to it's intended original (CAD) surface.

Thank you in advance for your answer.

Regards

Paul