I recently asked a question here, but in retrospect I'd rather have asked it at StackOverflow. Should I just ask the same question there, or request in my question to have a mod migrate it, or is there a better option?
Actually, mod_rewrite questions generally belong here, and it's fairly likely your dupe(don't do that) is just going to get migrated back.
But to answer the question: At your current rep level you can flag the topic for mod attention and request migration via the options. Later on, you'll also have access to close votes, with the same "off-topic" option available.