• If you know positions you can use STUFF function:

    SELECT STUFF('AD675498IJU76', 5, 0, '-')

    SELECT STUFF(STUFF('AD675498IJU76', 5, 0, '-'), 8, 0, '-')

    SELECT STUFF(STUFF('AD675498IJU76', 5, 0, '-'), 9, 0, '-')

    --Vadim R.