As the title implies, you can create an Exchange database through PowerShell in Exchange 2007. To do so you would use the New-MailboxDatabase command. When you use this command you will need to identify the name of the server and the server’s storage group to put the database on followed by the name of the database. For example the following command would create an Exchange database called YOURMOMSMAIL on KryptedServer in the Second Storage Group:
New-MailboxDatabase -StorageGroup “KryptedServerSecond Storage Group” -Name “YOURMOMSMAIL”