How to measure angle between atomic Planes

Hi,
I am a new user of Materials Studio, switching from Cerius2.
I want to measure distribution of the angle between the planes of two benzene rings (in a biphenyl molecule) from a trajectory file. In cerius2 it is done by accessing 'plane' in the measurement tool.

In Materials Studio I cannot find the option.
In MS bond distance, angle and torsion is there but plane is not available.

Can someone help me ?

Thanks
Mousumi