Flow of Old Sales Order and item values

Dear Gentlemen,

Account Based COPA activated and being used since 2010 in our client system.

As per the customer requirement,recently we have created two new charateristics ,viz;Sales Order and Sales Order  Item in COPA and values of Sales Order and its item are being flowing in to COPA.

But customer expecting to flow the values of OLD Sales Order and its items (i.e since 2010) for the above stated new two new characteristics.

Can anybody throw some light on this as how to bring the values of old sales oredrs and it items.

Regards

Su