Reconciliation is killing me !!!

Could someone please help me generate a report in R/3 through which I could match my numbers in BW. The Report in BW is based on a Purchasing Cube. But the KF I have to match (CO ACtuals) is a virtual keyfigure taken from an ODS from Controllong side. Now, How do I dig to the bottem of this??? I'm stuck badly on this issue.