[Zope] Using Mozilla with Zope - External Editor

A previous post regarding Mozilla reminded me of a problem I was having only a short while ago. If I'm using Mozilla, and I also have Zope External Editor, how can I set things up so that when I click on the little pencil icon in the management screen, the document pops up in Mozilla Composer instead of a text editor or some other application? I have Zope WebDAV enabled. TIA. Samir.