I'm having a hard time picturing what you're asking. Since as far as Excel would care "Joel" would not only be a mismatch to "Joell", but also to "Sam", "Gorge", "Bob", ... and pretty much anything other than "Joel".

that asside, the VBA to update cell comments would look something like this:
Sub Commenting_A_cell()
    Dim c1 As Range, c2 As Range
    Set c1 = ActiveCell
    Set c2 = Range("C4")
    c1.AddComment "In column C as: " & c2.Value
End Sub