Write a Form Handling Script in PHP -- 2

Looking to write a form handler Script which can receive HTTP/XML post from a server and post it to another server after making some modifications. The job involves getting data from a Landing Page Platform and Posting it to a CRM. A direct posting will not work because of the difference in how both servers are set up. And for the same reason we are looking to code a script which can act as an handler between these 2 servers. Posting instructions will be provided for both servers. We have done this in the past and can give you examples of what we did. We can't use it here because the CRM is different this time. Probably this only involves making adjustments to our existing script to match the new posting requirements.