If Cell in Range Contains Value Then Insert Comment in Adjacent Cell

Question

I hope the title clarifies the objective. All of my attempts fail miserably, for example:

Private Sub Worksheet_Change(ByVal Target As Range)

    With Range("A1:A10") = "blah"
        Range("A1:A10").Offset(0, 1).AddComment "fee"
        Range("A1:A10").Offset(0, 2).AddComment "fi"
        Range("A1:A10").Offset(0, 3).AddComment "fo"
    End With

End Sub

I have also tried this approach:

Private Sub Worksheet_Change(ByVal Target As Range)

    For Each cell In Range("A1:A10")
        If cell.Value = "blah" Then
            cell.Value.Offset(0, 1).AddComment "fee"
            cell.Value.Offset(0, 2).AddComment "fi"
            cell.Value.Offset(0, 3).AddComment "fo"
        End If
    Next

End Sub

And this:

Private Sub Worksheet_Change(ByVal Target As Range)

    With Range(Target.Offset(0, 1).Address).AddComment
        Range(Target).Offset(0, 1).Comment.Visible = False
        Range(Target).Offset(0, 1).Comment.Text Text:="fee"            
    End With

End Sub

Note that the code is intended to be an event handler inserted in a particular worksheet. I clearly misunderstand VBA syntax with respect to ranges. Any assistance in making any of these subs work would be most appreciated.

Follow up: Tim's suggestion to use Worksheet_Calculate worked like a charm. I was able to accomplish my objective with this final variation on Tim's code:

Private Sub Worksheet_Calculate()

    Dim rng As Range, cell As Range

    'see if any changes are in the monitored range...
    Set rng = Range("A1:A10")

    If Not rng Is Nothing Then

        For Each cell In rng.Cells
            If cell.Value = "blah" Then
                cell.Offset(0, 1).AddComment "fee"
                cell.Offset(0, 2).AddComment "fi"
                cell.Offset(0, 3).AddComment "fo"
            End If
        Next

    End If

End Sub

Answer 1

Private Sub Worksheet_Change(ByVal Target As Range)

    Dim rng As Range, cell as Range

    On Error Goto haveError

    'see if any changes are in the monitored range...
    Set rng = Application.Intersect(Target, Me.Range("A1:A10"))

    If Not rng is Nothing Then
    'Next line prevents code updates from re-triggering this...
    '  (Not really needed if you're only adding comments)
    Application.EnableEvents=False
    For Each cell In rng.Cells
        If cell.Value = "blah" Then
            cell.Offset(0, 1).AddComment "fee"
            cell.Offset(0, 2).AddComment "fi"
            cell.Offset(0, 3).AddComment "fo"
        End If
    Next
    Application.EnableEvents=True

    End If

    Exit Sub

haveError:
    msgbox Err.Description
    Application.EnableEvents=True



End Sub