The following are examples of the Add-ExchangeAdministrator command.
The first example adds the user Ted to the OrgAdmin role.
The second example adds the user Iliana to the ServerAdmin role on the Exchange 2007 server, Contoso-Mail-01.
Add-ExchangeAdministrator -Role OrgAdmin -Identity Contoso\Ted
Add-ExchangeAdministrator -Role ServerAdmin -Identity Contoso\Iliana -Scope Contoso-Mail-01