Update OCRB via SDK

Hi expert

i want to update the OCRB bank account via sdk. i've a simple file excel with 4 columns

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the code is ok but Sap doesn't update nothing

Dim Retval As Long

        Dim bp As SAPbobsCOM.BusinessPartners

        Set bp = oCompany.GetBusinessObject(SAPbobsCOM.BoObjectTypes.oBusinessPartners)

        Row = 2

        Do While ActiveSheet.Cells(Row, 1) <> ""

        bp.BPBankAccounts.BPCode = ActiveSheet.Cells(Row, 1)

        bp.BPBankAccounts.BankCode = ActiveSheet.Cells(Row, 3)

        bp.BPBankAccounts.InternalKey = ActiveSheet.Cells(Row, 2)

        bp.BPBankAccounts.AccountNo = ActiveSheet.Cells(Row, 4)

        bp.BPBankAccounts.Country = "IT"

        If bp.BPBankAccounts.BPCode <> "" Then

                Retval = bp.Add

            End If

        Row = Row + 1

        Loop

        oCompany.Disconnect

    End Sub

Cardcode is already insert in Sap b1 and i want to update the OCRD bank account

can anyone help me