New-MailboxExportRequest Format/name off exported .pst file

Environment: Exchange 2013

Hi everyone,

im preparing a bulk mailboxexport. Everything is working fine, but currently running the export will generate the following filename: @{Alias=BryaTest}.pst  

And im trying to find a way to generate DisplayName.pst  or Alias.pst or something like that. So, that exporting a mailbox with Alias BryaTest will create Bryan Test.pst, or BryaTest.pst

This is the ps1 im running: (generated with information from another topic here)

$mailboxes=import-csv c:\temp\bulkmailexport.csv

foreach($mailbox in $mailboxes)
{

New-MailboxExportRequest -Mailbox $mailbox.alias -FilePath "\\VM-Server01\c$\temp\$Mailbox.pst"

}

And the contents of the .csv file:

Any help would be great!