Export email to pst (Date range)

New-MailboxExportRequest -ContentFilter {((Received -lt '08/01/2012') -and (Received -ge '08/01/2011')) -or ((Sent -lt '08/01/2012') -and (Sent -ge '08/01/2011'))} -mailbox user -filepath \\mbsrv\e$\c.pst