Appointments+ - Selecting Service Providers

WPMU Team,

Is it possible to customize Appointments+ such that it ONLY allows repeat clients to schedule an appointment with a specific Service Provider. I would like to create an additional line(s) or checkbox that says - Are you first time or repeat client? If first time, then service booking by default goes through dummy Service Provider (Office Admin) who will select the appropriate Service Provider for client appointment request. If repeat client, they have choice of selecting from available list of Service providers (this request also gets routed to the Office Admin for confirmation).

Thx
-dale