reporting profit margin

hi, i have problem with reporting of the hidden profit margin. I have a cube with data:

invoice number, inv.item, margin

1, 1, 250

1, 2, 250

1, 3, 250

2, 1, 10

2, 2, 10

2, 3, 10

i have problem displaying it in Bex, the result has to be:

1, 1, 250

1, 2, 250

1, 3, 250

result inv.1, margin 250

2, 1, 10

2, 2, 10

2, 3, 10

result inv.1, margin 10

result of all invoices 260

thanks for help