Find normal vector and type it in txt file using NXOpen .NET

[MikeM78]

Hi,
I am trying to make a program in C# using NXOpen api in order to be able to select with the mouse any point on a face and extract the coordinates of the normal vector at this point. The aim is to be able to select successively many points and write their coordinates in a txt file.

I can select a point and display the normal vector coordinates at this point using Analysis->Geometric Properties. I would like to use the same type of filter that "Geometric Properties" command uses but i do not know what functions in C# to use nor how to set up the filter.

I have found and tested a program that allows the selection of a sketch. It uses the function "SelectObject" with
"scope=WorkPart",
"SelectionAction=ClearAndEnableSpecific",
"Selection.MaskTriple with type=UF_sketch_type, subtype=0, SolidBodySubtype=0"
Must I use the function SelectObject in order to find the normal vector or some other function?
What arguments must I pass in the function in order to have the same freedom in the selection of the point that I have when using the "Analysis->Geometric Properties" menu command?

Thanks in advance for any help.

Mike