[Zope] Programatically Adding 3rd Party Products?

Since reinventing the wheel is a waste of my time, I'd like to use VarImage (seen here:http://www.zope.org/Members/terry/) for some of my dynamic image resizing needs. However, to do this, I need to be able to programatically create VarImage objects via Python scripts. I'm not entirely sure if I can do that. The attempt at cheap and easy solution, replacing calls to manage_addImage with manage_addVarImage, did not work). Is there something I need to do with the product to make its constructor usable in such a fashion? Thanks, Edward