Like this ?

WITH CTE(reference,StartDate,Pattern,PatternLength) AS

(

SELECT 'TestRef-AA',convert(datetime,'01/01/2013 10:45'),' 1111 111 11','15'

SELECT 'TestRef-AA',convert(datetime,'10/11/2013 09:00'),'11 11 111 ','12'

SELECT 'TestRef-AA',convert(datetime,'09/09/2013 13:00'),'11111 11 ','9'

SELECT 'TestRef-AA',convert(datetime,'02/08/2013 12:00'),'1 11 1 ','11'

)

🙂