How to make a slave disc for starcraft(ASAP)?

my dad told me about something called a slave disc for the game starcraft. this might nto be the correct term, so sorry. he described it as, a disc that allows your friends to play starcraft, but only if the owner of the original game is online. for example. i burn my friend one of these discs, and he can play me on battlenet, but only when i'm online. please explain what this is and how to make one. ASAP