setting a request header based on post parameters

Hi,
I'm working on an apache filter that monitors the web server activity.
as part of participation with pther parts of the monitoring application, it sets a request heaader based on the url parameters. till here it is simple.

the problem is that on post requests coming from html form submittal, it should set the header also based on the post parameters.
When the apache serves as a proxy to other WS, e.g. mod_wl_22.so, the header that my filter sets is not passed to the other WS.
my guess is that the proxy module reads the headers from the apache before this heeader is set and already writes them to the socket to the other WS, so even though the header is validly set in the apache, it is not read by the proxy module.

any idea how to overcome this?
Many Thanks.

Hi nitz,

Can you explain what you are trying to achieve?

Please can you clear your explanation so that i can give you better suggestion which might solve your issue.

I'll try to enhance my explanation.
Our application monitors applications performance of different tiers.
there is a component that monitors j2ee applications and web server and there is a component that monitors the Apache web server performance, which is the filter I was describing.
in order to have a connection between the components monitoring the same transaction, we set a header in the Apache, and read it in the j2ee component.
the content of the header is some manipulation on the URL and its parameters.
On post requests of forms we'd like to do the manipulation also on the post parameters sent in the request body. if we wait till the post parameters are read by the proxy module, the header we set is not sent to the j2ee web server.
Hope that now it is clearer ,
we seek a way to be able to both read the post parameters and set the header so it will be passed to the J2ee web server.
Thansk,