[Zope-dev] Acquisition in a DTML Tag

I've defined my own dtml tag (i.e. <dtml-foo></dtml-foo>) and I am trying to look up an object depending on the arguments passed to my tag. The python class that defines the tag inherits from Acquisition.Implicit, but 'self' doesn't contain any of the Acquisition hiarchy. It seems like this must be possible, since the <dtml-var> tag must have to do an object lookup somewhere for objects passed to it to render. Can anybody shed some light on this? Is it doable? TIA -Brett