Track Cell History in Comment?

Perhaps you can adapt this:

Private Sub Worksheet_Change(ByVal Target As Range)
    Const sRng      As String = "A1:A10"    ' change as required
    Dim sOld        As String
    Dim sNew        As String
    Dim sCmt        As String
    Dim iLen        As Long

    With Target(1)
        If Intersect(.Cells, Range(sRng)) Is Nothing Then Exit Sub
        sNew = .Text
        Application.EnableEvents = False
        Application.Undo
        sOld = .Text
        .Value = sNew
        Application.EnableEvents = True

        sCmt = Format(Date, "yyyy-mmdd") & ": Was """ & sOld & """ is """ & sNew & """"

        If .Comment Is Nothing Then .AddComment

        With .Comment.Shape.TextFrame
            iLen = Len(.Characters.Text)
            .AutoSize = True
            .Characters(Start:=iLen + 1).Insert IIf(iLen, vbLf, "") & sCmt
        End With
    End With
End Sub