CableOrganizer.fr is an online retailer selling wire managagement
products in France.  When a customer purchases a product from us, we
would like to offer them "La Poste" (the French Post Office) as a
delivery option.  Unfortunately, we are unable to find an automated
way of computing these rates.

We need to find the information needed to either 1) link into La
Poste's rate calculator and send back the rates to our website, or 2)
Get access to always updated rate tables so that we can calculate the
rates ourselves.

A complete answer will provide us either of those two objectives. 
Please note, if you find the rate tables, they must be in electronic
format.  Remember, our web server will be accessing them.  Printed
rates or Adobe files would not work for us.  Also, a link to La
Poste's rate calculater will not help us either unless, we have the
information available to automote our commerce query.

http://www.laposte.fr/lapostepratique_n-2_particulier_calculer_tarifs.php3

there u go, i can also send  u a scan of the papers

That's a very good start but we can not use the web page as our
interface.  No human can be involved.  We need to be able to
automatically interact with the rate server to send the rates back to
our shopping cart.  Do you have documentation that would explain to us
how to interact with this script?

In other words, we need to pass the parameters to the php script and
have the rate server send back the appropriate rate.