How to make Office VBA code interact with a VSTO application-level add-in

Code Public partial class ThisAddIn
{
Protected override object RequestComAddInAutomationService ()
{
Return new AutomationServiceFactory ();
}
}
[ComVisible (true), ClassInterface (ClassInterfaceType. None)]
Public class AutomationServiceFactory: IAutomationServiceFactory
{
/*
Sub RaiseAddinEvent ()
Dim service
Dim vbaevent

Set service = application. comaddins. Item ("exceladdinstudy"). Object
Set vbaevent = service. Create ("")
Vbaevent. Raise ("thanks ")
End sub
**/
Public object create (string objectid)
{
Return new VbaEvents ();
}
}
[ComVisible (true), InterfaceType (ComInterfaceType. InterfaceIsIDispatch)]
Public interface IVbaEvents
{
Void Raise (string @ event );
Void UpdateVertical (string @ event );
Void ApproveVertical (string @ event );
Void SaveQuota (int @ event );
}
[Comvisible (true), classinterface (classinterfacetype. None)]
Public class vbaevents: ivbaevents
{

Public void raise (string @ event)
{
MessageBox. Show (@ event );
}

Public void updatevertical (string @ event)
{
VerticalMappingToolView vt = new VerticalMappingToolView ();
Vt. UpdateVertical ();
}
Public void ApproveVertical (string @ event)
{
VerticalMappingToolView vt = new VerticalMappingToolView ();
Vt. ApproveVertical ();
}

Public void SaveQuota (int @ event)
{
QuotaSave. Save (@ event );
}
}