How to cost an assembly in SW2013

If I have created an assembly of a bunch of parts in SW 2013 and have used the costing feature on each part stipulating materials etc, can you generate a single costing report from the assembly. It may be possible but I havent figured it out yet. Pronest (Nesting software) for e.g will generate a single report of all the parts into one report with a single figure. At the moment I am having to open or print off each parts report seperately and add then up. When in an assembly the costing feature tells me it is not available in assembly mode?

Thanks

SolidworksCosting