Try ringing Voda, they used to unlock some phones for free for current customers. Dunno if they still do but worth a call.
If not try a search on torrent sites for Blackberry unlock or something similar. Should find you the generator you need.
Once you've got the code then just do the following:
With the SIM in, hit the berry key and select Options, then Advanced Options. Scroll down till you find SIM card and select it. One that screen type in M E P D (you wont see any text whilst you type), then follow that by typing M E P 2 (Alt key + E/2 key). You should now be prompted to enter your, 8/16 character, unlock code. Done.