Option Explicit
Dim oCCTarget As ContentControl
Private Sub Document_ContentControlOnEnter(ByVal ContentControl As ContentControl)
  Set oCCTarget = ContentControl
End Sub
Private Sub Document_ContentControlOnExit(ByVal ContentControl As ContentControl, Cancel As Boolean)
  Set oCCTarget = Nothing
End Sub
Sub Increment()
  If Not oCCTarget Is Nothing Then
   Select Case oCCTarget.Range.Text
     Case Is = vbNullString
       oCCTarget.Range.Text = 1
     Case Else
       If IsNumeric(oCCTarget.Range.Text) Then
         oCCTarget.Range.Text = Val(oCCTarget.Range.Text) + 1
       Else
         oCCTarget.Range.Text = 1
       End If
  End Select
 End If
lbl_Exit:
  Exit Sub
End Sub