One further consideration is that if you plan to fly the HSI indications whilst coupled to a Flight Director or Autopilot, you probably should set the course that you plan to fly (180 with a 'from' flag in your example).
The reason is that most auto systems that I've seen would have trouble interpreting the electronic signals from the beam bar deviation and supplying a sensible correction if the aircraft heading was more than 30 or 40 degrees from the desired course. The systems can cope with a bit of drift but 180 degrees may be asking a bit much.
Of course, our clever human brains have no trouble in doing this, which is one reason why we are still employed to sit up front (thank goodness)!