[Zope] Import class in External method

Hi, I had some weeks ago a nice discussion on " Howto import external class in an external method ". However, I use now the " http://www.zope.org/Members/4am/instancehome " method to run my site. This really cool ;) In these condition, I would like to use something similar to import modules. If I want import a class placed in **my Zope root** tree the question is : where to place this module to import it ? I put my module in " MyZopeRoot/Products/Foo/ " and the call in the external method is " from Foo.mymodule import * " or " import Foo.mymodule " but nothing works. I stress I have also created a __init__.py in " MyZopeRoot/Products/Foo/ " but nothing has changed. Any track, FR.