VBA - AddComment

Public Sub main()
  Dim oRange As Range
  Dim oComment As Comment
  Dim sText As String
  
  'Use object variable to hold range.  In this example Sheet1 Cell A1
  Set oRange = Sheets("Sheet1").Range("A1")
  'Use object variable for comment
  Set oComment = oRange.Comment
  'text to be added to the comment box
  sText = "Hello"
  
  'If Sheet1 Cell A1 has a comment then appeng "Hello" to the end of the comment text
  If Not oComment Is Nothing Then
    sText = oComment.Text & sText
    oRange.Comment.Delete
  End If

  'Add a comment with the contents of sText
  oRange.AddComment sText
End Sub