I'd like to edit the Title, Subject, & Custom Properties of some files.
right now *.dwg & *.xls.

What's the object or API to use to access the files document properties.
(You know the ones where you right click a file and go to the custom or
summary tab and look at the metadata, i.e. Title, subject etc).

I'd like to to be able to retrieve the data as well as write to it.

Could someone help get me started in the right direction here.