Access - digitos bancarios

Una cuenta bancaria tiene 20 digitos. Tengo una formula en excel que permite calcular si los 20 digitos son correctos pero no se como hacerlo en access. Si alguien tiene una manera de hacerlo agradeceria me lo envien o me lo expliquen.

AHI TIENES ESTA FUNCION:
Function sBankControlDigit(Bank As Variant, SubBank As Variant, Account As Variant) As String

Dim sBank As String
Dim sSubBank As String
Dim sAccount As String
Dim Cuenta As String
Dim Temporal As Integer
Dim i As Integer

sBank = Format(Bank, "0000")
sSubBank = Format(SubBank, "0000")
sAccount = Format(Account, "0000000000")

If IsNull(Account) Then
Else
For i = 1 To 10
If Mid(Account, i, 1) = "." Then
sBankControlDigit = "**"
Exit Function
End If
Next
Cuenta = sAccount
End If

On Error GoTo ControlErrores

Temporal = 0
Temporal = Temporal + Mid(sBank, 1, 1) * 4
Temporal = Temporal + Mid(sBank, 2, 1) * 8
Temporal = Temporal + Mid(sBank, 3, 1) * 5
Temporal = Temporal + Mid(sBank, 4, 1) * 10
Temporal = Temporal + Mid(sSubBank, 1, 1) * 9
Temporal = Temporal + Mid(sSubBank, 2, 1) * 7
Temporal = Temporal + Mid(sSubBank, 3, 1) * 3
Temporal = Temporal + Mid(sSubBank, 4, 1) * 6
Temporal = 11 - (Temporal Mod 11)

If Temporal = 11 Then
sBankControlDigit = "0"
ElseIf Temporal = 10 Then
sBankControlDigit = "1"
Else
sBankControlDigit = Format(Temporal, "0")
End If

Temporal = 0
Temporal = Temporal + Mid(sAccount, 1, 1) * 1
Temporal = Temporal + Mid(sAccount, 2, 1) * 2
Temporal = Temporal + Mid(sAccount, 3, 1) * 4
Temporal = Temporal + Mid(sAccount, 4, 1) * 8
Temporal = Temporal + Mid(sAccount, 5, 1) * 5
Temporal = Temporal + Mid(sAccount, 6, 1) * 10
Temporal = Temporal + Mid(sAccount, 7, 1) * 9
Temporal = Temporal + Mid(sAccount, 8, 1) * 7
Temporal = Temporal + Mid(sAccount, 9, 1) * 3
Temporal = Temporal + Mid(sAccount, 10, 1) * 6
Temporal = 11 - (Temporal Mod 11)

If Temporal = 11 Then
sBankControlDigit = sBankControlDigit + "0"
ElseIf Temporal = 10 Then
sBankControlDigit = sBankControlDigit + "1"
Else
sBankControlDigit = sBankControlDigit + Format(Temporal, "0")
End If

If Len(Trim(Cuenta)) < 10 Then
sBankControlDigit = "**"
Exit Function
End If

For i = 1 To 10
If Mid(Cuenta, i, 1) = "-" Or Mid(Cuenta, i, 1) = "." Then
sBankControlDigit = "**"
Exit Function
End If
Next

Exit Function
ControlErrores:
sBankControlDigit = "**"

End Function

ok Gracias