Powershell script to move mailboxes from exchange 2003 in child domain to exchange 2010 in parent domain

Scenario:

domain.com(Primary domain with primary domain controller ad01.domain.com)

child.primary.com(Child domain with domain controller ad02.child.domain.com)

Ex01.domain.com(Exchange 2010 servers on primary domain)

Ex02.child.domain.com(Exchange 2003 server on child domain)

Db01( Database on Ex01 server).

St01(Mailbox store in First Storage Group on Ex02 server).

Question:

I want to move all the mailboxes on mailbox Store St01 to database db02 through Exchange cmdlets/powershell scripts .How can I accomplish this?

Thanks in advance.