HIGH - Need to convert old POs and Receipts into existing open period with Orginal PO Creation date

Hi Experts

HIGH - Need to convert old POs and Receipts into existing open period with Original PO Creation date and Receipt Date

We are converting 2 years purchase orders and 4 years receipts( few are invoiced and few not yet invoiced)

1: PO created on 26-Mar-2016 in source system , today(19-Jan-2017) converting the PO into Oracle but need to convert the PO as po creation date. order creation date as 26-Mar-2016

  and here PO periods, GL periods inventory periods  for MAR-2016  already closed

2; Similarly  Receipt created on 26-Mar-2016 in source system , but  today we need to convert the receipt in to Oracle where receipt creation date as 26-Mar-2016