I just tried this. I am not sure if it is what your looking for but it may be a start in the right direction

select to_date('020202', 'YYMMDD') from dual;

Result
TO_DATE('
---------
02-FEB-02

to use to_date you give it the date string that you are receiving and also the format that the date string is in. In my case I was giving it Year month day so the format was 'YYMMDD'

You can try to toss that into your insert and see what happens