Original Cost Transaction date when Burden Applied

 Hi
 I have a question on Burdens. Would appreciate if someone can help me with the answer.

we add a burden to each item that we purchase using donor funding.  This burden is a in effect a mark-up or Overhead cost.  AC61 applies a specific burden to the cost when the cost is posted.  Since the new custom program is changing the structure of  burdens the costs, we need to make sure that the burden is applied at the same exchange rate as the original cost.

Can someone tell me what is the original cost transaction date when the burden is applied. I looked at ACTRANS table for the transaction date, but my client mentioned that burden would have a original cost trans date when Burden is applied.

Thanks
Kamal