bdc problem

Hi,

Iam trying to upload the data into VA02 transaction.

I want to update the open(order) quantity....va02 >123456 >schedule line items(4th icon from right down).

How to find which quantity was open programmitically.?So i can update that paricular line item order quantity..

code something like this.

select edatu from vbep into table t_date where vbeln = w-vbeln.

loop at t_det. ( dialog program itab )

loop at t_date. ( table itab )

if t_det-MBDAT = t_date-edatu.

perform bdc_field using 'BDC_CURSOR'

'RV45A-ETDAT(01)'.

perform bdc_field using 'RV45A-ETDAT'

t_date-edatu.

perform bdc_field using 'BDC_CURSOR'

'VBEP-WMENG(01)'.

perform bdc_field using 'VBEP-WMENG(02)'

VBEP-WMENG.

perform bdc_field using 'VBEP-WMENG(04)'

record-WMENG_04_007.

endif.

endloop.

endloop.

Any advice pls

cheers

kaki