Apache module for directory authorization

Hello. I'm looking for a simple Apache module
that connects to my PostgreSQL database to
determine if a given file is readable by a
browser having a particular cookie.

Specific details:

1. The user is already logged in with
a cookie. The cookie is a long hash
and within the database.

2. I have a stored procedure "canread"
which takes the cookie and the path
and returns true/false.

3. I'm looking for an apache module that
will connect, call my procedure and
then gives access to a particular
as appropriate.

In particular, I've found many postgresql
_authentication_ modules, but I've yet to
find a good _authorization_ module. That
is, most of them use the HTTP Authenticate
mechansim and check passwords to give access
to a whole sub-tree. My users are already
logged in (via a cookie) and my access
requirement is far more granular.

Any pointers?

Thank you so much,

Clark