'Converting' Halo from one language to another?


I have a question:

So, I'm thinking about hetting Halo for my Mac, but here I can only get the german version of the game. I test played it at a friends house, and did not like the synch work at all. My brother has the english version of the game for the PC, and I like the voice work much better. Som I was wondering:

If I get the german version, could I replace files with the ones from my brothers PC to get the english voices to my Mac? Has anyone infos or expiriences on this?

Thanks for any input in advance! :)