Converting Exchange contacts to Exchange users using PowerShell

I am converting 250 Exchange 2010 contacts to Exchange users. I have researched and am very close to a solution.

This is my command to export the contacts;

Get-Contact -organizationalunit "ourschool.edu/contacts" | select DisplayName,FirstName,Lastname,WindowsEmailAddress| Export-Csv c:\exportcontacts.csv

After deleting the contacts, I then add a password column to the CSV file and import as users with this command;

Import-Csv exportcontacts.csv | ForEach {New-MailUser -Name $_.DisplayName -DisplayName $_.DisplayName -FirstName $_.FirstName -LastName $_.LastName -ExternalEmailAddress $_.WindowsEmailAddress -UserPrincipalName $_.WindowsEmailAddress -Password (ConvertTo-SecureString $_.Password -AsPlainText -Force) -ResetPasswordOnNextLogon $false -OrganizationalUnit "ourschool.edu/Student Email"}

The problem I have is I also need to export...