Option Explicit
Private WithEvents m_oThisApp As Application
Private Sub Class_Initialize()
  'Syncronize class with application.
  Set m_oThisApp = Word.Application
lbl_Exit:
  Exit Sub
End Sub
Private Sub m_oThisApp_DocumentBeforeSave(ByVal Doc As Document, SaveAsUI As Boolean, Cancel As Boolean)
Dim oDialog As Dialog
  If ActiveDocument.AttachedTemplate = ThisDocument.AttachedTemplate Then
    Cancel = True
    Set oDialog = Dialogs(wdDialogFileSaveAs)
    With oDialog
      .Format = 13
      .Show
    End With
  End If
End Sub