Auto create SubTask in 'Email to Task' when task has the same Subject Line

Often times, our initial email is sent to create a task by ‘Email to task’ method.

However, we still communicate with the user/customer via email and it would be great to auto add as a subtask when forwarding an email with the same Subject line as the initial email.

This will keep communications in the same ‘thread’ of tasks instead of creating ‘new’ ones.