Atharv Joshi
Forum Moderator
Hi Philipp, 
 
Yes, its possible to measure the angle between the faces and XZ plane and get the output in excel.
Once you measure the angle, you can use "if loop" to filter out faces based on measured value.
 
Can you please share the screenshot of the geometry so that I can help you better?
What exactly do you want as output in excel the measured value of angle for all faces or the moment of inertia? 
 
Regards
Atharv