PUTs and Proxies

I am attempting to combine proxying with GETs & PUTs, but I am a novice
at proxying, so I would appreciate any help you can offer.  The scenario is:

Client requests are handled by my own resource class, which is (in theory)
installed as the root resource (an extension of HTTPResource or FileResource).
To process a request, the resource decides whether to GET or PUT the file,
or to perform some other action, based on external criteria.  If the URL
points to a foreign server, the GET/PUT is referred there, where a "pure"
Jigsaw (without my extensions) will hopefully handle the request, using
FileResource's GET or PUT method.

As a novice to proxying in Jigsaw, my questions are: can my new resource
invoke jigsaw's proxying capabilities in the middle of an ongoing request
(when a foreign server is indicated), and if so, what actions are required? 
And would the original request create a new GET/PUT request on-the-fly for
the foreign Jigsaw, or can it just redirect itself to the foreign Jigsaw?   


   -- Thanks in advance, 	

        Gordon Dakin