Modify Standard Cost Allocation fields in Summary Payment Applications BP

we would like to ask if it's possible to add Data Elements on a BP of Summary Application type.

as you know, once creating a Line item, it is possible to add Lump Sum or Unit Cost types.

when select Unit Cost, the below Data Elements are shown:

- Cost Code (bItemID)

- Cost Name (bi_item)

- Short Description 8short_desc)

- Quantity (uuu_quantity)

- Unit Cost (uuu_unit_price)

- Amount (amount)

which exporting the xml for integration are appearing under a new section (_cost_allocation) , under _bp_lineitems

<_cost_allocation>

<bItemID></bItemID>

<bi_item></bi_item>

<short_desc></short_desc>

<uuu_quantity></uuu_quantity>