Custom Exchange 2010 RBAC for Hide from Exchange Address Lists and Message size restriction

Dear Fellows,

I need to create a custom RBAC management role on Exchange 2010. Rights required are to allow the helpdesk staff to enable/disable the "Hide from Exchange Address Lists" and apply message size restrictions to Exchange mailboxes.

Does any one know which ManagementRole/ManagementRoleEntry I need to use as a parent, for my custom ManagementRole?

Any thoughts/help will be highly appreciated.

Thanks.

J.A