Sub HeadingSentenceCase()
' Paul Beverley - Version 18.02.20
' Sentence cases this selection or paragraph (but not acronyms)

trackIt = True

allowAreaSelection = False

highlightChange = False
If Selection.Start = Selection.End Or allowAreaSelection = False _
     Then Selection.Expand wdParagraph
If Len(Selection) < 3 Then
  Selection.Collapse wdCollapseEnd
  Beep
  Exit Sub
End If

myTrack = ActiveDocument.TrackRevisions
If trackIt = False Then ActiveDocument.TrackRevisions = False

myEnd = Selection.End - 1
Selection.End = Selection.Start + 1
' Skip past <> codes
If Selection = "<" Then
  Do
    Selection.MoveRight , 1
  Loop Until Selection = ">"
  Selection.MoveRight , 1
End If
While LCase(Selection) = UCase(Selection)
  Selection.MoveRight Unit:=wdWord, Count:=1
  Selection.MoveEnd wdCharacter, 1
Wend
myStart = Selection.Start
Set rng = ActiveDocument.Content
Set rng1 = ActiveDocument.Content

For i = myStart + 1 To myEnd
  rng.Start = i
  rng.End = i + 1
  If Len(rng) > 0 Then
    a = Asc(rng)
  Else
    a = 0
  End If
  If a > 64 And a < 91 Then
    rng1.Start = i + 1
    rng1.End = i + 2
    a = Asc(rng1)
      If a > 96 And a < 123 Then
        rng1.Start = i - 2
        rng1.End = i - 1
        If Len(rng1) > 0 Then
          a = Asc(rng1)
        Else
          a = 0
        End If
        rng1.Start = i - 1
        rng1.End = i
        b = Asc(rng1)
        If Not (a = 46 Or a = 33 Or a = 63 Or b = 13 Or b = 9) Then
          rng.Text = LCase(rng.Text)
          If highlightChange = True Then rng.HighlightColorIndex = wdGray25
        End If
      End If
  End If
Next i
ActiveDocument.TrackRevisions = myTrack
Selection.Start = myEnd + 1
End Sub