Contact CDV, they may be willing/able to exchange it. Don't expect a fast response... Check with someplace locally you might be able to replace it; maybe they could work something out with their distributor or directly with CDV.

If not, most of the contents of the '..\Divine Divinity\Run\localizations\english' folder are small enough to email, though not the voice.cmp file (153MB). Mixing files may give you text in english and voices in german, or it could crash the game. Another person did the same thing, but I never heard back if/how they resolved the situation or if they tried mixing files.

As a last resort, see German for Beginners. <img src="/ubbthreads/images/graemlins/evilgrin1.gif" alt="" />