DECLARE @cadena varchar(max) SET @cadena= 'AB1CAB2CA7274743B3C' SELECT @cadena AS Cadena

SELECT CHARINDEX('B', @cadena) AS PosB1 , CHARINDEX('B', @cadena, CHARINDEX('B', @cadena) + 1) AS PosB2 , CHARINDEX('B', @cadena, CHARINDEX('B', @cadena,CHARINDEX('B', @cadena) + 1)+1) AS PosB3 , SUBSTRING(@cadena,CHARINDEX('B', @cadena),2) AS Str01 , SUBSTRING(@cadena,CHARINDEX('B', @cadena, CHARINDEX('B', @cadena) + 1),2) AS Str02 , SUBSTRING(@cadena,CHARINDEX('B', @cadena, CHARINDEX('B', @cadena, CHARINDEX('B', @cadena) + 1)+1),2) AS Str03