How can i copy and paste 100 item lines into Purchase order (ME21N) ?

hi,

Can anyone help me to use the copy and paste from Microsoft excel ?

1. i have 100 line items in excel for material item.

2. I copied the 100 lines in excel and paste into PO creation transaction code ME21n line items.

3. In one shot, i only successful copied 35 lines.

How can i manage to copied all line items into PO items in one shot ?

Is it possible to copied the excel line items into PO screen line item more than what we can see in the screen ?

thanks