Post XML to a website

I have to post XML to a website from my Iseries running V4R3.

I have the XML document all ready to go.

When I asked how I post it, they gave me a sample .HTM file.  Here is the 
important part:

<form action="http://xxx.xxx.xx.xxx/Integration/Integration.asmx/Populate"; 
method="post">
                        Paste Full Route XML here:
                        <br>
                        <textarea name="varPayload" cols="100" rows="50">

They have little knowledge about how to do it from a server.  He said one 
customer did it with a Unix box and he put varPayload =
"populate" or something.

Has anyone done this?  I was hoping to use either Scott Klements or Brad's 
GetUri.

Thanks.
_________________
Art Tostaine, Jr.
CCA, Inc.
Jackson, NJ 08527