Ask a new question that's focused on the thing you've actually been searching for. It seems like it wouldn't be a duplicate because you're actually looking for something else than the question in which you found the relevant information. Having several questions that can be answered similarly, i.e. with the same tools, is fine. Also, asking questions to which you know the answer is fine (see http://meta.tex.stackexchange.com/q/4/4012), I think there's even a blog post about that by one of the SE overlords.

I don't think we want people highlighting stuff in other people's answers that they think is important. If you think an important aspect of an answer isn't highlighted enough, you can post a comment to the answerer, proposing clarification; but I don't think this is the case here. Answers are only highlighted as a whole, in comparison to other answers: On the one hand by the OP choosing an accepted answer, on the other hand by all users upvoting (and downvoting) answers.

Ask a new question that's focused on the thing you've actually been searching for. It seems like it wouldn't be a duplicate because you're actually looking for something else than the question in which you found the relevant information. Having several questions that can be answered similarly, i.e. with the same tools, is fine. Also, asking questions to which you know the answer is fine (see Asking a question and answering it yourself straight away), I think there's even a blog post about that by one of the SE overlords.

I don't think we want people highlighting stuff in other people's answers that they think is important. If you think an important aspect of an answer isn't highlighted enough, you can post a comment to the answerer, proposing clarification; but I don't think this is the case here. Answers are only highlighted as a whole, in comparison to other answers: On the one hand by the OP choosing an accepted answer, on the other hand by all users upvoting (and downvoting) answers.