[Zope] Local FS manage_addFolder woes

[Chris Withers]

Hi, I'm trying to create a folder within a localFS object if one doesn't exist already.

I'm trying:
<dtml-if "not localFSobject.fileIds(folderNameVar)">
 <dtml-call "localFSobject.manage_addFolder(folderNameVar)">
<dtml-else>
 Folder exists...
</dtml-if>

The problem is that this creates the folder in the folder containing the localFS object, not in the
localFS object.

Do I want a dtml-with? If so, which one? 
Does LocalFS support manage_addFolder or is the above happening because it doesn't and so aquisition
is causing manage_addFolder to be executed on the folder object containing the localFS object? If
aquisition is hapening, what should I use instead of manage_addFolder?
Am I totally up the wrong tree?

Any help is good help...

Chris