Hi Jenny,
In Business Edition the VM account is truely tied to the creation in CUCM as a first step;
Creating User Accounts in a Coresident Configuration
In Cisco Unified Communications Manager Business Edition (CMBE), you create individual users and administrator accounts on the User Management pages in Cisco Unified CM Administration. The accounts are based on the templates and classes of service that you create and/or modify in Cisco Unity Connection Administration.
Users with voice mailboxes are end users; users without voice mailboxes are system administrators (or application users). After you add an end user for Connection, you can then configure an end user voice mailbox in Cisco Unified CM Administration. Other settings can be modified as needed from the user account pages in Connection Administration.
http://www.cisco.com/en/US/docs/voice_ip_comm/connection/7x/user_mac/guide/7xcucmac080.html#wp1056521
Hope this helps!
Rob