Sub AddSectionNumber()
' Paul Beverley - Version 07.02.11
' Add indexed section number

afterText = Chr(9): ' a tab

Dim v As Variable, i As Integer
varsExist = False
For Each v In ActiveDocument.Variables
  If v.Name = "indexNum" Then varsExist = True: Exit For
Next v

If varsExist = False Then
  ActiveDocument.Variables.Add "indexNum", 1
End If

' If no text is selected ...
If Selection.Start = Selection.End Then
' Add an index number
  i = ActiveDocument.Variables("indexNum")
  Selection.HomeKey Unit:=wdLine
  ' Selection.PasteAndFormat (wdFormatPlainText)
  Selection.PasteSpecial DataType:=wdPasteText
  Selection.TypeText Text:="." & Trim(Str(i)) + afterText
  Selection.HomeKey Unit:=wdLine
  If Selection = Chr(9) Then Selection.Delete Unit:=wdCharacter, Count:=1
  ActiveDocument.Variables("indexNum") = i + 1
Else:  ' if some text is selected ...
  ' set up a new index number
  i = Val(Selection)
  If i = 0 Then i = 1
  myInput = InputBox("Start number?", "Section numberer", Trim(Str(i)))
  If Len(myInput) = 0 Then Exit Sub
  i = Val(myInput)
  ActiveDocument.Variables("indexNum") = i
End If
Selection.End = Selection.Start
End Sub