T-SQL funciton to calculate CUSIP check digit

IF  EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[fn_GetCusipCheckDigit]') AND type in (N'FN', N'IF', N'TF', N'FS', N'FT'))
DROP FUNCTION [dbo].[fn_GetCusipCheckDigit]
GO

SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

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-- Author Date
-- Steven Rao 2013-08-08
---------------------------------------------------------------------------------------------------------------
-- Return the check digit for a CUSIP number
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-- Reference:
-- http://social.msdn.microsoft.com/Forums/sqlserver/en-US/c55474df-6908-4d05-bf23-7b341bd7994f/user-defined-function
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-- Test script:
--DECLARE @Sample TABLE ( Cusip CHAR(9) );
--INSERT INTO @Sample
--VALUES ('14149YAR9')
-- ,('000020347')
-- ,('126650BG4')
-- ,('254709AC2')
-- ,('437076AQ5') ;
--SELECT *, dbo.[fn_GetCusipCheckDigit](LEFT(Cusip, 8)) as CheckDigit FROM  @Sample ;
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CREATE FUNCTION [dbo].[fn_GetCusipCheckDigit]
(
@Cusip CHAR(8)
)
RETURNS CHAR(1)
AS
BEGIN
RETURN
(
SELECT (10 - SUM(s/10 + S%10) % 10) % 10
FROM (
SELECT s=(NULLIF(CHARINDEX(substring(@Cusip, V.number, 1), R.Ref),0) -1) * (2 - V.number % 2)
FROM master..spt_values V CROSS JOIN
(SELECT Ref='0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ*@#') R
WHERE V.type='P' and V.number BETWEEN 1 AND 8
) SQ
)
END

GO