ActiveX Control Containers: Inserting a Control into a Control Container Application
Before you can access an ActiveX control from an ActiveX control container application, you must add the ActiveX control to the container application using the Insert ActiveX Control dialog box.
To add an ActiveX control to the ActiveX control container project, see Viewing and Adding ActiveX Controls to a Dialog Box.
Once you add the control, you need to add a member variable (of the ActiveX control type) to the dialog box class. For more information on this procedure, see Adding a Member Variable.
Once you have added the member variable a class, referred to as a wrapper class, is automatically generated and added to your project. This class is used as an interface between the control container and the embedded control.