I was having the same problem

I found out how to identify what was selected.

Private Sub Timer1_Timer()

On Error GoTo ErrorHandler

dim shp = Map


If TypeOf MPC.ActiveMap.Selection Is Object Then

Set shp = MPC.ActiveMap.Selection
'if the selection is not a shape, it will fail and go to the ErrorHandler
'if not you have the line selected.

' do what you want
' you can determine what line it is if you named your line or put text in

end if

ErrorHandler:

End Sub