Grouping items in Master Planning

1.

I have below scenario---

item       Quantity

A                 7

A                 4

B                 3

B                 2

When i Firm a purchase order the system creates 4 lines in PO. Is there any way of creating only 2 lines with accumulated quantity.

2. Also I want to know that is there any way to select all proposed orders of different items and Group ?

I have lot of lines of items in which a lot are duplicate.

So i want to select all and GROUP them so that system will give distinct items and i can firm the PO.

Thanks in advance...