Splitting a single posting

Is there some way available to split a single posting into more postings?
The use case is this. Say that a topic starter asks two unrelated questions in a single posting. It would make the discussion clearer to split such a question over two postings. Currently, I don’t see a way to do that. I can only start a new topic myself, and quote the original author with the second question. I think it would be nice if an admin could somehow duplicate an existing thread, and modify that thread in order to split a discussion.