How to Extend Parameter BAPIPAREX(Extension In) for BAPI

Hi,

I'm using BAPI_MATERIAL_SAVEREPLICA For Creating Materials.

In the BAPI there is an internal table EXTENSION type BAPIPAREX.

BAPIPAREX have below Fields

Structure

Valuepart1

Valuepart2

Valuepart3

Valuepart4

I have append custom fields into MARA Standard Table . Custom Fields length is above 1200 Characters.

Here I want to enhance the BAPIPAREX structure for 1200 Characters,

i.e. Add two extra fields in the Structure like VALUEPART5 & VALUEPART6

how do i achieve this enhancement ??

If Enhancement Category is not done in structure , What will happen ??

Regards,

Balakrishna Gajula