Macro to figure open area of a face

In case you haven't read my post in the general section Iwill explain my situation. I work for a company that designs partsfor pet food extruders. This will only apply to two components thatwe make. We have set blanks that we cut various shapes into and Iam needing to get SolidWorks to figure the open area and populate acustom property which will drive a note in a drawing.

I talked with my var today and they told me that this wasn't assimple as making an equation to drive a custom property, that itwould require a very in depth macro. I don't know and really don'thave the time learn right now. If anyone could lead me in the rightdirection, it would be great.

Thanks in advance,
SolidworksApi macros