Decorative Porch Posts Terminate on a Sloped Ceiling/Roof

[bmhobby]

I'm trying to design a front porch with decorative posts that support the gable end, but I cannot figure out how to get the posts to terminate on the angle of the roof plane. I am using a railing with the newels/posts set to Post to Ceiling. I played around with the Ceiling Platform settings to see if that changed anything, but when set to "Balloon Through Ceiling Above," the posts go to the top of the roof peak, rather than terminating along the pitch of the roof. The "Automatic" setting terminates the posts below the bottom of the roof. 

 

Is there a better way to create these types of posts other than using railings, or are there different settings I can try to fix the issue?

 

I have attached an image of the problem and an example of what I'm going for.

[PitMan71]

Use invisible walls to form the porch room and stone walls to form the columns. The stone walls all terminate at the roof the plane like your example shows.