Sub AddRoundedComment()
 Application.ScreenUpdating = False
 On Error GoTo ErrorHandler
 With ActiveCell
  .AddComment
  .Comment.Visible = True
  .Comment.Shape.AutoShapeType = msoShapeRoundedRectangle
  .Comment.Shape.Select True
 End With
 With Selection
  .Font.Size = 11
  .ShapeRange.Shadow.Visible = msoFalse
  .ShapeRange.ScaleWidth 0.6, msoFalse, msoScaleFromTopLeft
  .ShapeRange.ScaleHeight 0.3, msoFalse, msoScaleFromTopLeft
  .ShapeRange.Adjustments.Item(1) = 0.25
  .HorizontalAlignment = xlCenter
  .VerticalAlignment = xlCenter
 End With
 ErrorHandler:
 Application.ScreenUpdating = True
End Sub