Globals Class

When you create a VSTO Add-in using Visual Studio there is a Globals static class that gets generated automatically.
You can use this class to access several different components of the project at run-time.
This class is created for both document-level and application-level solutions.

Globals.ThisAddIn.Application 
Globals.ThisWorkbook 
Globals.ThisDocument 
Globals.Ribbons 
Globals.FactoryGetVstoObject 
Globals.FormRegions 

public void Event_Application_WorkbookActivate( 
   Microsoft.Office.Interop.Excel.Workbook oWorkbook) 
{ 
   ?? = new System.IntPtr(Globals.ThisAddIn.Application.Hwnd) 
} 

Globals.ThisAddIn.Application.WorkbookActivate += 
   Event_Application_WorkbookActivate;