[Zope] Adding a ZClass Instance to a Specific Folder

[Leichtman, David J]

The default constructor when a ZClass is created calls:
<dtml-with "ZClass_name.createObjectInFolder(REQUEST['id'],REQUEST)">
</dtml-with>
And when you programmatically add a ZClass instance, it's like this:
<dtml-with "manage_addProducts('Your_product')">
  <dtml-call "ZClass_name.ZClass_name_add(_.None,_)">
</dtml-with>
This creates the instance in the directory of the method from which the 
call was made.

The Question:
How do you go about adding an instance to a specific folder? I can't, 
for the life of me, figure it out. I've tried many different things, 
and I've looked for flags in createObjectInFolder, but to no avail.