Private WithEvents dm As DefaultSheetDataModel

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load　

　　With FpSpread1.ActiveSheet

              dm = CType(.Models.Data, DefaultSheetDataModel)

             dm.UnionedChangeCellRange = False

             .ReferenceStyle = ReferenceStyle.R1C1

             .Columns(2).Formula = "RC1 * RC2"

             .Rows.Clear()

             addingRow = True
             For i As Integer = 0 To 1

             　.Rows.Add(i, 1)
             Next
             addingRow = False

             SetValue()

             For i As Integer = 0 To 1

                    .SetValue(i, 0, 2)

                    .SetValue(i, 1, 500)
             Next

            FpSpread1.ActiveSheet.Columns(0).Locked = False
            FpSpread1.ActiveSheet.Columns(1).Locked = False
            FpSpread1.ActiveSheet.Columns(2).Locked = False

      End With

End Sub

Dim addingRow As Boolean = False
Dim lstIndex As List(Of Point) = New List(Of Point)
Private Sub dm_Changed(sender As Object, e As SheetDataModelEventArgs) Handles dm.Changed

      If (addingRow) Then
          lstIndex.Add(New Point(e.Row, e.Column))
          Return
      End If

     Dim rowIdx As Integer = e.Row

      Dim colIdx As Integer = e.Column

      If colIdx = 2 Then

          Me.FpSpread1.ActiveSheet.SetValue(rowIdx, 4, Me.FpSpread1.ActiveSheet.GetValue(rowIdx, 2))

      End If
End Sub

Private Sub SetValue()
      For i As Integer = 0 To lstIndex.Count - 1
            Dim rowIdx As Integer = lstIndex(i).X
            Dim colIdx As Integer = lstIndex(i).Y
            If colIdx = 2 Then
                Me.FpSpread1.ActiveSheet.SetValue(rowIdx, 4, Me.FpSpread1.ActiveSheet.GetValue(rowIdx, 2))
            End If
      Next
End Sub