Autodesk Robot Structural Analysis

[#1]

What is the best way to trim the column with an inclined roof without having to rotate the entire structure to get a straight roof and trim the column the rotating the structure back to it's original position.

[#2]

One of possible solutions - COM macro doing that:

http://forums.autodesk.com/t5/Autodesk-Robot-Structural/cutting-of-slanted-column/td-p/3048622