Это должно начать вас. Это работает с вашей пробной фотографией, но потребуется настройка, если источник комментариев - это другой лист.
Sub AddDates() Dim targetRng As Range, commentSrcRng As Range Dim strPrefix As String ' why this variable? You never seem to use it Set targetRng = Application.InputBox("Please select the target range. This is the range that will have comments added to each cell", Type:=8) Set commentSrcRng = targetRng.Offset(0, 3) ' from the screenshot. Will have to tweak if this is a different worksheet. Dim cel As Range Dim i As Long i = 1 For Each cel In targetRng If cel.Comment Is Nothing Then cel.AddComment End If cel.Comment.Visible = True cel.Comment.Shape.TextFrame.AutoSize = True cel.Comment.Text strPrefix & commentSrcRng.Cells(i) i = i + 1 Next cel End Sub