How to get the coordinate of a control point using automation?

Suppose I have a hull with 6 surfaces. I want to know the coordinate (x Value to be exact) of the control point (row=1, column=0) of the first surface. how can I get this using automation?

I am trying the following code.

msApp.Design.Surfaces.Item(1).GetControlPoint 1, 0, CPx, CPy, CPz

But getting this error.