Some kind of "proxy-tool" for Apps running inside Xnest?

Hi there,

I'm a happy user of ion, at home as well as at work.
Problem is: At work we're using the Citrix Client to be able to use
some Windoze applications from within Solaris.
Citrix is a hell of a X11 application. It resizes its windows, forces
window placement, movement and so on. It doesn't work very well with
many window managers, leading to placement errors, disappearing
windows. Or crashes.
With ion, the Citrix client is nearly unusable. Even if you create a
new workspace with an "empty" layout it's a mess. I won't blame ion
for this. There's no need for an application to handle window manager
tasks...

As a solution I created a fullscreen workspace and attached a Xnest to
it. The Citrix client uses Xnest without any window manager. So far
this runs pretty stable. I can recommend this way for every
misbehaving application.
The only thing that bothers me is that I don't get "window alarms"
(events), and that I can't access the individual windows inside Xnest
from ions controls.
Is there a tool that could do this, or that could be used as a starting point?

Regards
Christian