Chances are that the fuse link has blown in your cig lighter. If you follow the "AC bulb change" link in my sig, you will see how to get the ashtray out. On the bottom of the lighter socket, you will see a nut, undo the nut and take out the fibre washer that is sandwiched between the two metal discs. Pu thte nut back on and job done. That will bypass the fuse link. Mind you, if you just want the 12v, you wouldn't need to bypass the fuselink as the more than likely the actual power is there and working on the plug behind the lighter.
If you don't fancy doing that, you could pick up power from the digital clock display. Again, details to get that out is in the link I mentioned above. Failing that, you can use the stereo power, but that involves removing the head unit (details in the same link on how to remove it). There would also be power behind the mirror control, so that would be another option.