I bet ten thousand dollars that given the second computer, a working audio in/out cable connection between them, sufficient recording software on one machine, and iTunes and Realplayer on both, it'll work. Here's why: It's impossible for either computer to know that audio is being streamed from the Realplayer file on one computer into the other computer, because the audio connection can only send audio and in one direction. So there'll never be a message that says "You are not allowed to stream this audio" or "Port blocked because etc."
You can also use this same trick to get around the copy protection on iTunes Music Store purchases with an iPod, but you need to have an iPod. Note: I'm not advocating redistribution of protected media files, but rather telling you how to get around the protection so you can use the file for your own personal enjoyment without future complications.