[users@httpd] How to customize Apache Headers?

[Anand Kulkarni]

Hi,
 
I am sending many requests from TCP client to Apache. Using mod_proxy it
will be routed to the destinition server.
 
In every client request, I want to send different HTTP headers but I
found that Apache adds its own headers and does not allow client to set
request specific headers.
 
So, my question is How to customize Apache Headers from the client side?
 
regards,
 
Anand