I'm a bit late to the party so my suggestion is worthless now except for those that might take it for future consideration. Some defects are simply better off left alone. There's a fine line in determining the best course of action, if any.
In the case of the OP's defect I would have simply hand polished the scratch and if that didn't remove or improve it I would have stopped there.
Here's my reasoning...
1) The scratch on the door frame is right at eye level so any repair short of perfect is always going to be staring you right in the face.
2) Even if you could sand and polish the scratch out without going through the clear, the finish in that area would be so much smoother than the surrounding area that it would look as bad, if not worse, than the original scratch.
3) Repainting the section is an option, but also a compromise. Color match, texture match, and the durability of the refinish vs. the factory finish should all be considered before exercising this option.
For the OP, you're stuck with the repaint option at this point.