How to aggregate subitens details in the main item

Hi Gurus,

Imdoing a shipment with batch partition. When doing this the picking quantities are 0 in the main item because you have to fill picking quantities in batch partition soyou can choose how much do you want from each batch. The thing is inbatch partition you get 3 item lines (1 main item and 2 subitem) and when you fill the subitem picking quantities you let the quantities in the main item with 0, something like this:

My problem is that whenImdoing invoice the same thing goes copied:

What I need is to find a way to sum up both thequantites and net value so that it appears in the main item line. In thiscse it should be

ITEM 10                                                  20           | UN  |                180,00

Appreciate any kind of help.

Thanks in advance,

António