Exclude mount paths

Hi folks,

I try to set path exclusions for my Microsoft Defender.

That works for "normal" folders and their subfolders.

Now I have several external disks mounted under a subfolder, e.g. I got C:\mounts\ and under there I have several mount points: C:\mounts\disk01, C:\mounts\disk02, C:\mounts\disk03 etc. with disks mounted.
So I tried to list C:\mounts\ under exclusions hoping it will automatically exclude subfolders. 

But that does not work.

How to exclude disk mount points that are mounted unter a normal subfolder?

Thanks,