can jigsaw point all requests at one servlet?

Hi:

I've just started using servlets and jigsaw.

How do I configure jigsaw to route _all_ incoming requests to the same
servlet? 

I want to be able to do some initial processing universally on every
request sent to the jigsaw server. I want to "proxy" all hits through my
"entry" servlet.

Is it possible?

thanks in advance.

-rob