Function getSedolCheckDigit(Input1) Dim mult(6) As Integer mult(1) = 1: mult(2) = 3: mult(3) = 1 mult(4) = 7: mult(5) = 3: mult(6) = 9 If Len(Input1) <> 6 Then getSedolCheckDigit = "Six chars only please" Exit Function End If Input1 = UCase(Input1) Total = 0 For i = 1 To 6 s1 = Mid(Input1, i, 1) If (s1 = "A") Or (s1 = "E") Or (s1 = "I") Or (s1 = "O") Or (s1 = "U") Then getSedolCheckDigit = "No vowels" Exit Function End If If (Asc(s1) >= 48) And (Asc(s1) <= 57) Then Total = Total + Val(s1) * mult(i) Else Total = Total + (Asc(s1) - 55) * mult(i) End If Next i getSedolCheckDigit = Input1 + CStr((10 - (Total Mod 10)) Mod 10) End Function