total for line data

Hi All,

We are using BW 3.5 and SAP R/3. Data for sales is updated in BW as line data.

Plant Bill Till Article NetAmt

1 1 1 a 10

1 1 1 b 15

1 1 2 c 20

2 1 1 c 20

3 1 1 a 10

Now we want

Plant Bill Till NetAmt

1 1 1 25

2 1 1 20

3 1 1 10

1 1 2 20

How to add line data while loading?

Thanks

Regards: Gaurave