I'm sure it can be done in SSIS but any "is date" function my have problems depending on what it thinks a date is. To get around that, you may have to use both ISDATE and a pattern match to guarantee the correct format.

Borrowing heavily on Lowell's test data (which you should supply in this format in the future), here's how to do it in T-SQL. I'd do it for you in SSIS but I don't even know how to spell it correctly. 😛

WITH MySampleData (Eid,Variable)

AS

(

SELECT '1','na' UNION ALL

SELECT '2','none' UNION ALL

SELECT '3','4/18/2013' UNION ALL

SELECT '4','18/2013' UNION ALL

SELECT '5','2013' UNION ALL

SELECT '6','9999999'

)

SELECT Eid,Variable

FROM MySampleData

WHERE 1 = CASE

WHEN ISDATE(Variable) = 1

AND Variable LIKE '[0-9]%/[0-9]%/[0-9][0-9][0-9][0-9]'

THEN 1

ELSE 0

END

;