Set Default Audio Conferencing phone number per region or group

We're adding a few thousand audio conferencing licenses to our tenant soon. We'd like the default phone number to be set based on the user's region or group. For example, when we create a new user in Denver, we'd like the number to automatically be assigned the Denver phone number.

Is it possible to automatically set the default audio conferencing phone number based on region or group?

If we can't configure based on region or group any help with using PowerShell to set the phone number would be helpful as well.

Thanks,

John