Reducing recipient addresses when sending to lot of recipients using Outlook 2010

Our email client is Outlook 2010. The email server consists of Exchange 2003 and Exchange 2010. We are being migrated from Exchange 2003 server to Exchange 2010. We don't want to have the recipient addresses in BCC field, but also don't want all of them to be appearing on the TO or CC field.

 The reason for not expanding all addresses is less people respond to an email which is sent to many people. Sending the messages to each individual would be too time consuming.

Our Exchange server administrator, does not have time to create server distribution mailing lists for us and the
 client distribution mailing lists expands the addresses to all recipients when the email is sent.

 Mail merge is not an option, if I am understanding how it works http://blogs.office.com/b/microsoft-outlook/archive/2008/09/22/mail-merge-how-to-send-a-personalized-e-mail-to-many-people-at-once.aspx correctly.

 Is there a way we can use a client distribution mailing lists?

We need the message to be sent TO employee_list(which is list of employees who are emailed) and CCed to manager_list(which is list of managers of those employees).

The recipients can expand the address, if they want, when they receive the message.

Thanks