Active Roles (ARS) can perform basic administration of 'Exchange Unified Messaging', however, there doesn't appear to be any method by which "other extensions" can be added to a user's Exchange Unified Messaging config:
Whereas, it is possible through Microsoft Exchange's own Admin Centre:
対策
WORKAROUND: None
STATUS: Enhancement request number “761797" has been submitted to Development for consideration in a future release of Active Roles.