V8: Adding ContextMenu ability to unbinded TextBox?

Does anyone know how to add the context Menu ability to an unbinded TextBox?  Through the developer mode, I have attempted to add Part.PartNum to EpiContextMenuKey property of a Textbox that I have added onto the UD01Form.  This attempt is not working.  Is there a way to do this through code instead of using the Property Window?

Any ideas?

Thank you,

Dan Godfrey