Php :: Flash HTTP Requests URL Containing RTMPE URL - Get A Local Copy Or A Copy With Content?

A web channel streaming service streams to a certain IP range, it only checks the IP in example.com/cmd.php?id=xxx (channel number) and outputs an rtmpe stream URL, nothing else.How do I trick it to get my local URL instead of the one on their server? I have considered squid proxy, but is there some way to do it with a firefox plugin or greasemonkey script?

Edit:I will try to specify:It's a streaming service from an ISP and cable provider. They stream for free to people on their IP's. On their webtv page, which is called webtv.example.com, there is a flash player. If you are not on an IP from their ISP, you can't stream anything but the test channel.When you try to change channel via. javescript:videoplayer_changechannel(xxx) it makes this HTTP request:

[URL]

If you are on one of their IP's you will get an RTMP URL, like this:

[URL]

This is what the flash player requests, and if it get's this response it load the channel requested. There is no HTML on the php page, just the URL. Note that the rtmp URL is static.If you are not on one of their IP's it will return a random sentence (something stupid, the programmers having fun).I wan't to trick the flash player into getting the right value, even though it's not on one of the ISP's IP's.