delete the records which have the Data values are NULL before load data to BPC model

Hi Everyone,
I am loading the data from flat file to BPC Model (10.0 Version).
Source data (Flat file) looks like below:

RP_Employee RPT_Currency Data
Test                USD                   8
Test1              USD
Test2              USD                    6

My user requirement is that to delete the records which have the Data values are NULL before load data to BPC model.

So,Please let me know how can i meet to this requirement.

I am thinking that,it is possible by using start routine BADi. If i am correct please let me know process like creation of class and BADi implementation.

Thanks in advance!!