[Zope] Duplicates

Hi, my problem is that I have a site with information which should be displayed in two parts of my tree structure. Like this: - a - b - c (1st. subtree) - d - e - f - g - h (2nd. subtree) - i - j and the content in c and h should be the same. But I don't want the files (methods or whatever) in both subtrees, but to refer from h to c without the user in h realizing that he is in the other subtree. This means, I don't want a real copy of the content (because of update effort)... Any suggestions? Thanks in advance... Martin