i am working on a macro that draws a bounding box around a part and returns stock size for me in terms of a custom property. it is working just how i like in part files but i would really like to be able to Ctrl select multiple parts in an assembly, run the macro and then have the stock sizes written into the individual part properties.  something similar to using the custom property tab in the task pane in 2009.

is this possible?  if so please help!