Sub PunctuationToComma()
' Paul Beverley - Version 25.03.23
' Changes the next punctuation item to a comma

trackIt = True

searchChars = ":;."

newChar = ","

myTrack = ActiveDocument.TrackRevisions
If trackIt = False Then ActiveDocument.TrackRevisions = False
Set rng = Selection.Range.Duplicate

For i = 1 To 1000
  rng.MoveEnd , 1
  If InStr(searchChars, Right(rng, 1)) > 0 Then
    rng.Start = rng.End - 1
    gotChar = True
    Exit For
  End If
  DoEvents
Next i
If gotChar = False Then
  Beep
Else
  rng.Delete
  rng.Select
  Selection.TypeText Text:=newChar
End If
ActiveDocument.TrackRevisions = myTrack
End Sub