HTTP Header

Hello,

Is there any way to modify the default HTTP Header? For instance, I would like to change this:

POST https://example.org/service/submit HTTP/1.1
Content-Type: text/xml;charset=UTF-8
SOAPAction: ""
User-Agent: Jakarta Commons-HttpClient/3.1
Host: example.org
Content-Length: 81776


To this:
POST https://example.org/service/submit HTTP/1.1
Host: example.org
Content-Type: text/xml
Content-Length: 81776
SOAPAction: ""

The order is important to me because of how the application handles it.

Thanks for the help!