Custom AHRS_Orientation parameter

I need some help here.
Im trying to set the AHRS_Orientation parameter to Roll180 and Pitch45. And for the external compass Pitch45. But 45 is not a number listed on the AHRS_ Orientation for Pitch. The option 100 says is for customization but I don’t know how to do this. Any help???

In less words, I need to set the AHRS_Orientation to Roll180Pitch45. And the external compass to Pitch45.

Thank you guys!