[Zope] variable propagation

Hi, I would like to ask how to propagate variables from initial index_html call to deeper levels. Say I have index_html python script, I invoke it then I would like to feed some data to "generic" template, that will in turn will invoke template in the same directory that will do nice layout of my results. Generic template lies below all other objects, in directory tree, in the root. When I execute the command chain, variables are not passed and options is lost on one layer of zpt calls. Is there way to rectify that. Thanks Pavel