What you are looking for is a ticket system. Posting it to a thread is a malformed idea IMHO, because your main point of reference is forum functionality.
If you would have it posted to a thread and you would be able to respond trough the thread, then you would need custom thread fields, departments, issue status, etc. All the things a support ticket does.
I'd like to highlight the similarity between this need, and the need for a post report center. Both are needs for functionality where users need to submit an issue to the staff and staff needs to handle it and give feedback to the user.
Giving us tools to streamline contact between users and staff would be a live saver. I currently use Kayako (Costed €700 so far) and while its a huge improvement to email, it doesn't meet the needs of an active forum.