cost element report

Hi FICO Guru

Could u plz help me on this issue.

Problem---- Here they have created one Expense A/C for almost 6 months back and made so many posting in that account but same account is not created as Cost Element in CO.

So all such posted amounts are not coming in Cost Element reports.

Now they have created it as a cost element so now onwards whatever posting in that G/L account is coming in cost element report,the problem is how to pull earlier posting made in G/L account in this cost element report.

Kindly suggest how to solve this problem.

Thanks & Regards

Gyanesh