[mod_python] server (internal) redirect

I'm using the publisher handler to construct a page that has SSI 
(server-side include) code in it.  Once the page is built I want to then 
run it back through the server.  Just setting

    req.content_type = text/x-server-parsed-html

doesh't do it.  Any suggestion?

Please note, I'm NOT talking about an HTTP redirect;  I'm talking about 
returning something to the publisher that will let it know it needs to 
run the output back through the server so that the SSI code can be 
processed before sending it back to the client.

TiA,

Nick