[Zope] External Methods

[DS]

Hi, I am just learning Zope, and I wanted to try external methods.  I
first tried a symlink in the Extension directory, but zope reported it
couldn't find it.  I then copied the file into the Extension directory
and was successful at that.  I assume that happened that way perhaps for
my own protection.  Is that true?  Or, is there a better way to do
that?  I have a project directory where I have been working on modules,
and I was hoping to avoid copying them periodically to Extensions as I
test one thing or another.

My next question is that I import other modules within the module that I
just mentioned.  I have copied them over to Extension, but still have an
error that they are not found.  Am I trying to do something prohibited
with Zope.  What controls that?

Thanks very much for any help you can give me.

ds