standard cost rollup


I am new to Ax2009 standard costing method. I need advice for the functionality.

Let sat i have a simple BOM 2 level. All is setup with standard costing.

Level 0. FG  , std cost USD 20

        Level 1. SubBom , std cost USD 20

                     Level 2. Rawmat A, Std cost USD 5

                     Level 2. Rawmat B, std cost USD 15


If let say, i re-valuate the Rawmat A, Std cost to USD 7.

If there any function in Ax2009 that can help us to roll up the cost for Level 1 and Level 0  ?