This field will not be copied automatically. The reason for this is
1. Send teh Quotation to the customer
2. Customer reviews the Quotation and confirms the order and then releases the Purchase order
3. Create sales order for this PO.
Hence the PO Number maintained in the Quotation is not copied automtically into the Sales order.
You can copy this using the Copy control routine at item level/header level. In the copy control routine, you can pass the PO value in to the sales order.
In our case what happens a quote is created with reference to a PO and at the item level in the order data tab, the PO item no is there. this has to be copied to the order when the quote is referenced.
Which data transfer rountine or copying requirement should i modify in the copy control at item in VTAA?
You need to change the include FV45C102 (assuming you have copied standard order and the copy controls). ABAP team should be able to make changes to this routine and achieve your requirement.
In VTAA, after choosing the Source and Target order type and choosing the right Quatation item, check the routine for 'Bus.data/item compl.' and it will be what has been mentioned above.
Hope this helps