Dude I've been hangin over this problem also, along with another thread 
http://forums.contribs.org/index.php?topic=25160.0I've yet to see a working solution.
I got my proxypass to work by adding
 ProxyPass /othersite/ http://otherserver/ 
<Location>
 order deny,allow
 deny from all
 allow from all
</location>to a httpd.conf template in /etc/e-smith/template-custom/httpd/conf/httpd.conf/atemplate - path is from memory so may be out a bit
note tho that when you restart the httpd the main httpd.conf file is'nt always updated from the template so check it if nothings working, if it doesnt update, I suggest deleting the template then edit the main httpd.conf directly.
This method should take you to the index page on the other server, to access further pages is the problem as links will have to be hardcoded with the outside url rather than just the dir path. eg
<a href="http://globalserver/othersite/apage.html">apage</a>
rather than
href="apage.html">apage</a>This of course would screw up viewing the pages from inside the network. I'm working on the problem, but if anyone else has an idea to solve please feel free to divulge.