I have noticed that, for the most part, when random idiots are speaking of creationism versus evolution, they have simply got their terms wrong.
What they really mean is, creationism versus the entirety of science. Biology, physics, cosmology, chemistry etc...
They are all underattack.
And usually we respond with something like..
"That has nothing to do with evolution."
Compltely accurate and reasonable, from a scientiific stand point. From their stand point those are questions we don't want to answer. Which they will interpret as questions to which we have no answer.
As an alternative then, I would suggest this. We point out that they are asking a physics, or chemistry question. And challenge them to admit that they are opposed to science in general. Many people would, probably, be less willing to admit that, than they are to admit that they simply don't like evolution.
The Anti-Creationism Guild