how to fill null,zero with default value

Hi,

I would be thankfull if any one can solve my question please.

i have one table having date as field with  records as below

                                date

                            2010-09-11

                             2010-08-12

                            Null

                           0

now my problem is i have to load all the fields into oledb destination but

null and 0 should be loaded with any defalut value but for both null and 0 i should get same defalut value

thanks in advance

vandana