Instance Data from Microstation element

Is it possible to add instance data to an element from Microstation, so that the volume of the element is included in Datagroup explorer?

I know that I could technically take this information out through Family/Part & quantify, but it would be so much simpler if it could be done via. instance data. So that I can have all of my quantity data in one place. Another reason this would be great, is that datagroup data is exported into the 3D PDF and .imodel format. Where Family / Part data is not.

These are special elements that cannot be made with the ABD tools. I don't care about length/height and so on. Only volume.

/Michael