Hi Janet
I would still challenge the business requirement.
Generally we don´t bring the cost factor into APO because you would like to planning and not constraint them with budget. You could always bring the information in Reporting to valuation of stock.
But if you still want, I would not prefer play around with CIF as we don´t have real time cost valuation.
You can use the BW extraction process to extract the Cost information once a day to make it at least easy and robust development.
Please let us know if this information helps you.
Thanks
Amol