The simplest approach may be to intercept Word's Document_Close event, but you'd need to supply the logic for which rows to process.
Although Word has a 'Selection Change' event that you might be able to leverage, it fires for every selection change, so you'd need to code it so that it only does anything under the appropriate conditions. It also entails the complications of creating a class module and event procedure. For more, see:
https://wordmvp.com/FAQs/MacrosVBA/AppClassEvents.htm
Your code might look like:
Code:
Private Sub oApp_WindowSelectionChange(ByVal Sel As Selection)
Application.ScreenUpdating = False
With Sel
'Do your processing here
End With
Application.ScreenUpdating = True
End Sub
Do note, too, that you'd also need to code for the processing to be based on the last cell/row previously selected.