Adding ActiveX control to powerpoint via Interop.

I have an ActiveX control that installed on my machine, and can be added from PowerPoint via:

Developers->Controls->More Controls->"My control".  
I want the user to be able to add the ActiveX (my control) via Custom button on the Ribbon.  
I successfully added a button to my custom Ribbon (VSTO). but I can't find a way to make this button adding "My Control" to the slide.
I also successfully added an Excel sheet by calling:  

    Shapes.AddOLEObject(1, 1, 100, 100, "Excel.Sheet", "", MsoTriState.msoFalse, "", 0, "", MsoTriState.msoFalse);

but I can't fint the appropriate way to add my custom ActiveX.