If I understand your request correctly, this may be helpful to you

CREATE TABLE #Dob(birth VARCHAR(15))

INSERT INTO #Dob

SELECT '24-10-2012' UNION ALL

SELECT '01-01-2011'

SELECT birth AS 'Input',

REPLACE(birth,'-','/')AS 'Converted' FROM #Dob

Results:

Input Converted

24-10-201224/10/2012

01-01-201101/01/2011