I think the best way would be to simply transfer the song files to the pc. The pc and mac are obviously networked. But for the mac, you need to designate that you will allow certain areas of your computer are shareable to another computer. At least that is true for osx 10.5 Leopard. I am not knowledgeable about networking with a pc. But I would imagine the same thing would apply. So once you transfer the files across to the pc, direct your Mylo to that location to copy the files.

But then again, if it is a mac osx network permissions issue, then if permissions are set correctly, your pc and Mylo will probably be able to read directly from the LW download folder.