Private Sub Workbook_SheetBeforeRightClick(ByVal Sh As Object, ByVal Target As Range, Cancel As Boolean)
Dim MyComments As Comment
Dim lArea As Long
For Each MyComments In Sh.Comments
With MyComments.Shape
.TextFrame.AutoSize = True
If .Width > 300 Then
lArea = .Width * .Height
.Width = 200
' An adjustment factor of 1.1 seems to work ok.
.Height = (lArea / 200) * 1.1
End If
End With
Next MyComments ' comment
End Sub