You can use either of these events depending on the passed parameters that you may need.
VB Code:
  1. 'Behind ThisWorkBook
  2. Private Sub Workbook_SheetBeforeDoubleClick(ByVal Sh As Object, ByVal Target As Range, Cancel As Boolean)
  3.  
  4. End Sub
  5.  
  6. 'Behind a Sheet
  7. Private Sub Worksheet_BeforeDoubleClick(ByVal Target As Range, Cancel As Boolean)
  8.    
  9. End Sub