In their Personal Excel book, in the ThisWorkbook Code page, declare an App Object 
Option Explicit

Public WithEvents ThisApp As Application
 
Private Sub Workbook_Open()
    Set ThisApp = Me.Application
End Sub

'This one is tested as written
Private Sub ThisApp_WorkbookOpen(ByVal Wb As Workbook)
   'Do stuff
End Sub

'This one is not
Sub ThisApp_SheetBeforeDoubleClick(ByVal Sht As Object, ByVal Target As Range, Cancel As Boolean)

If Sht.Parent Is ThisWorkbook Then Exit Sub

'If all Workbook will have the same Root
'If not Sht.Parent.Path = ??? Then exit Sub

'If all have a similar name part
'If not InStr(Sht.Parent.Name, NamePart), then Exit Sub

'Do Stuff

End Sub