I am searching for suggestions about how you can do this. I wish to possess a server sit among the customer and also the actual server. For instance:

Client -> Proxy Type Server -> Web Server.

So in exchange the net server would pass leads to the proxy server which in exchange provide the results to the customer. For instance:

Client <- Proxy Type Server <- Web Server

This is a diagram whether it makes existence simpler:

A diagram

Whether it only agreed to be simple GET demands no problem but I am unsure the way it works when the client was posting data. I really hope someone can advise me about this. Thanks if you're able to!

I am unsure what your real question is... Should you setup a proxy server involving the client and also the application server, then it will likely be exactly that: a proxy server. Therefore it will proxy demands towards the application server, just like you've proven inside your diagram. If your client POSTs data towards the proxy, the proxy server will POST that same data towards the application server and return the reaction to the customer...

Are you currently asking how to setup something similar to this?

EDIT: I am likely to have a wild guess here...

Whether it only agreed to be simple GET demands no problem but I am unsure the way it works when the client was posting data

Would you imply that the customer is POSTing to a PHP or Ruby script around the "Proxy Server", and never an actual proxy server like Squid or Apache's mod_proxy? If that's the case, are you currently asking how, using PHP, to transmit that Publish data towards the application server? If that is your question, here's the solution:

<?php

$application_server = '1.2.3.4'; // replace with IP or hostname of application server
$uri = $_SERVER['REQUEST_URI']; // you may need to change this, not sure from your question.

$curl = curl_init("http://{$application_server}{$uri}");
curl_setopt($curl, CURLOPT_POST, 1);
curl_setopt($curl,CURLOPT_POSTFIELDS,$_POST);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, TRUE);

$data = curl_exec($curl);

// do something with $data, transform it however you want...

echo $data;