Hello Forum,
I think I may already know the answer to this but I'd like to confirm from other experts. Customization of the Convert_to_Case.aspx page in CRM 2011 in not supported by Microsoft. The issue I am having is that when I try to convert an appointment to a case
(on premise web version) the Customer field in the Convert_to_Case.aspx page only gets prepopulated when we set the 'Required' field on the appointment. Otherwise, the regarding field will not prepopulate the lookup.
Is there a supported way to have the Regarding field on Appointment activities be set as the value of the Customer field in the Convert Appointment to Case (Convert_to_Case.aspx) window?
This appears to work well with Phone Call activities, but not with Tasks or Appointments.

Any guidance is greatly appreciated.
Regards,
Axel