I know there are other topics - one of which I posted - however I need specific help. My apologies.

I'm on 2017 and using a VB.NET AddIn.

I have a point data extractor that re-curses the Feature Tree of a Part and returns X, Y, Z data for several DATUMPOINT's ("Point" Features). No sketch involved, thus no transform from Sketch to Model. All is well.

A user now wants this data relative to a user defined Coordinate System. No problem - I've added a ComboBox populated with any Coordinate Systems found in the model.

What I don't get - and I'm sure it's a fundamental block - is specifically how to do the Transform to a User Defined Coordinate System, which is selected in the ComboBox by name, let's say "Mikes Coordinate System";

So, I have an oPoint as a MathPoint populated with default coordinates.

How do I transform this Math Point's coordinate array from the default coordinate system to the user defined coordinate system "Mikes Coordinate System"? An example would be great - I'm stumbling on specifics, like how to get the 'transform' for the user selected coordinate system in the ComboBox.

So close yet so far... Any help much appreciated!