Can the "Database is mandatory for user mailbox" be resolved using PowerShell

Hello Experts,

Here is the issue Im encountering.  Im in the process of testing an Exchange migration from Exchange 2000 to Exchange 2007.  Ive successfully restored my AD into a lab environment and verified AD is working correctly.  Ive semi-successfully restored Exchange 2000 into the lab environment.  What has happened with the Exchange 2000 restore is approximately 200 of 1000 mailboxes restored correctly (they show up in the Exchange System Manager) and work perfectly in lab.  When I open AD Users and Computers on my lab Exchange 2000 server and access one of the users whose mailbox is among the 200 mailboxes showing up in Exchange 2000 System Manager and click on the Exchange General tab, I see the following information:
Mailbox Store:
Exchg2000/First Storage Group/Mailbox Store (Exchg2000)

Note: Exchg2000 is the name of the Exchange 2000 server

 When I access one of the users whose mailbox is not among one of the 200 mailboxes showing up in the Exchange 2000 System Manager and click on the Exchange General tab, I see the following information:
Home Server
Yavapai/Exchg2000/Exchg2000

Note:  Yavapai is the name of the Exchange organization
Note: Exchg2000 is the name of the Exchange 2000 server

I have introduced Exchange 2007 into the lab and it is coexisting with Exchange 2000.  When I open the Exchange 2007 Management Console à Recipient Configuration à Mailbox, I see all 1000 mailboxes.  If I try to move one of the 200 mailboxes that I can see in the Exchange 2000 System Manager, the move is successful (moves can be don via the EMC or the Exchange shell).  If I try moving one of the 800 mailboxes that did not show up in the Exchange 2000 System Manager, then I get an error stating:  Database is mandatory on user mailbox.

To correct this problem, I do the following:
1.      Access AD Users and Computers on the Exchange 2000 server.
2.      Right-click on a user account whose mailbox is not among the 2000 listed in the Exchange 2000 System Manager
3.      Select the Exchange Tasks
4.      Select the Remove Exchange Attributes option
5.      Click <Finish>
6.       Right-click on a user account whose mailbox is not among the 2000 listed in the Exchange 2000 System Manager
7.      Select the Exchange Tasks
8.      Select the Create Mailbox option
9.      Verify the server information is as follows:
Yavapai/Exchg2000/Exchg2000

10.      Verify the mailbox store information is as follows:
First Storage Group/Mailbox Store (Exchg2000)

11.      Click Finish

Once this has been done, the mailbox can be moved to Exchange 2007.

Here is my question, is there a way to use powershell to script this process?

Regards,
Nick