Hud - well done for getting that far, the 13th is always a lucky day for me! Hope it all works out well, and that you can send them something! quickest, cheapest and easiest is download a free or shareware recording studio software package, record the song onto it, save it as a MP3 file and send it! You will need a computer microphone - available cheaply from most computer shops. Good luck and keep us posted!
Cheers, Lucy