CorelDRAW Graphics Suite X6 :: Cannot Index Shapes Array

I am writing a C# (.Net) app to auto create a CorelDraw document, by copying and pasting shapes from a document containing master copies of shapes, into a new document.

I have a simple VBA script that does this. And now I am trying to convert it to C# but I cannot get it to find the shapes from the Shapes array of the layer in the master document.

i keep getting error "Argument out of range".  The code is: string myShapeName = "round_green";

CorelDRAW.Shape myShape = masterDoc.Pages[0].Layers["Images"].Shapes[myShape];

The pages and layers arrays work (return the correct object). I seem to recall someone saying there was an issue with the COM objects returned by the Shapes array.   But in this case the error indicates the issue is with the indexer passed in - I have tried an integer (0) and a variable containing a string and neither work.