Call this function in your property page's DoDataExchange function to synchronize the value of an integer property with the index of the current selection in a combo box on the property page.
void AFXAPI DDP_CBIndex(
Pointer to a CDataExchange object. The framework supplies this object to establish the context of the data exchange, including its direction.
The resource ID of the combo box control associated with the control property specified by pszPropName.
The member variable associated with the property page control specified by id and the property specified by pszPropName.
The property name of the control property to be exchanged with the combo box control specified by id.
This function should be called before the corresponding DDX_CBIndex function call.