Single page PHP XML post and receive script

I have a short but sweet (15 lines in total) XML segment I need to post to a remote server, the data will be analyzed by the remote server (not anything you have to deal with, only the sending and the receiving back of the data) and the remote server will process the data and send the new data back to the local script here based on the data that was first sent from that same script to the remote server. This is really an API but I will be handling the posting the data to the script (which the script will then post to the remote server) using a form that sends the data to this script as POST data. The only thing you have to make this one single php page do is plug the POST data I send to it from a form into the spots using variables. Then the script needs to make the data it receives back postable to another page I just need the data received to be POST-able, easiest method I can think of is to make the received data formated into hidden form fields so the person viewing the page will just see the data, click continue and the data will be transfered to the next page. I can handle what the data does on the next page, I jsut need this one page to receive data I POST to it, it needs to stick the POST-ed data into the XML, send it to the remote server, receive the new XML data back in response to the POST-ed XML, stick that data into a form so that it can be sent via POST to a new page. I attached the XML as it will be sent, with all the fields, and the XML data that will be received, with all the fields that will be returned, and I was playing around looking for a way to do this and there is a PHP script that maybe you could work off of, I can not get it to work but maybe you can. I know it is missing some things filled in (like where it says [login to view URL] I know it should say something else) but I do not know. Look over all this data and see. Lowest price wins!