I don't really see the point of having a question and when clicking it, instead of going to the question going somewhere else.
Anyway, assuming the resulting URL varies per question, you might need to create a way to map each question ID to a resulting URL (unless the URL is OK with receiving the question ID). Then you could use a layer to modify the URL dynamically.
Based on your comment, in order to achieve your expectations you can follow these steps (assuming you're using the SnowFlat theme):
1. Locate this line: https://github.com/q2a/question2answer/blob/3320b653f94ffa1f004d51cc82f0e95f573ff411/qa-theme/SnowFlat/qa-theme.php#L365
2. Add in there this text:
$q_item['url'] = 'https://www.google.com/search?q=' . $q_item['title'];