Play on two computers.

Help me figure this out; I don't know where else to ask. I bought Heroes: Chronicles of Two Worlds because I wanted a game we could play online. I wanted to play with my dad. But here's the problem: the game doesn't work without the disc. Do you know what we can do to play on two computers using only one disc (the computers are connected via a local network)? How can we make a copy, or something? I don't want to spend money on the game again.