You can do what you describe iff you can get a UDP port opened through
what you describe as the "Firewall/NAT/Proxy" by which CIPE can tunnel
into the network.
You say you can't do that, in which case I'm afraid you're out of
luck. If you can, then your issues will revolve around routing and
probably ARP: You need to be provide for direction so as to route into
and out of the home network in question, and you will probably need
the CIPE endpoint machine inside that network to proxy-ARP on your
behalf using whatever IP address is appropriate within that network,
so as to accept and then deliver packets within that network destined
for your remote host not otherwise a part of the home network.