[Connect C#] How do I make an Annotation Cell?

When plotting a cell through the Bentley Cell window,  If the cell that has annotation,  I can plot that cell by unchecking "Place as Shared Cell" and a "Annotation Cell" element is created.

If I plot the same cell with the "Place as Shared Cell" option enabled, a "Shared Cell Element" is created.

If I plot a cell that does not have any annotation and have "Place as Shared Cell" unchecked, a "Cell" element is created.

For a SharedCellElement, I can call the "AddAnnotationScale" method and it will scale to the design file drawing scale properly.

CellHeaderElement does not have this method, the only thing I could do is scale the CellHeaderElement by the annotation scale, but this would not react to changes in the design file drawing scale.

When Bentley creates an "Annotation Cell" it reacts properly to the drawing scale, but I do not know how to create this element type.

CellHeaderElement has a getter for "IsAnnotation" property, but no setter.

How does one make an "Annotation Cell" using the DgnPlatformNet API?

Thanks,

Maury