equation in macro

every time i create a sheet metal part, i add an equation for square footage using the bounding box width and length.i would like to have a macro i can run that would do this for me to save some time. is this possible or has anyone made a macro that does this?


EDITED BY MODERATOR: Moved to the API/Macros space. Please  post to the appropriate space if one exists.

SolidworksApi/macros