Just to elaborate a particle or two, my understanding is that candlepower is related to focused beams of light, whereas lumens are not limited to beamed light output--therefore, it is very difficult to convert between the two.
I'll save you some time: given a candlepower measurement and a lumens measurement and no other information (which is the way it always is), the two are not convertible from one to the other. Ya, bummer!
And if I could be even more unhelpful: Since different manufacturers seem to measure candlepower and different distances, even comparing candlepower to candlepower is very often so misleading as to be nearly useless. And hey, a simple candlepower reading won't tell you what the beam is like: a beam highly-focused into a little laser-like point will be very bright, but may or may not be as useful for you as a beam that puts out more light overall, but is less focused and thus has a lower candlepower rating.