Exchange 2010 - How do I import .CSV as external contact records?

I administer multiple sites. These sites are not in our AD structure so we're creating external records in the GAL.

I was sent an .csv from each site, all in the following format.

Name          Email-Address                 FirstName     OfficePhone      Department  Title
Last,First     First.Last@domain.com     First             xxx-xxx-xxxx    IT                Painter I

I've looked around and I've found ways to import only the DisplayName/Email address but I would like to know how I can include the other attributes. Such as:

Import-Csv Contacts.csv | ForEach-Object -Process { New-MailContact -Name $_.DisplayName -External
EmailAddress $_.EmailAddress $_.Firstname -FirstName -OrganizationalUnit "OU\Email\External Contact Records" -Alias $_.DisplayName


Any Ideas?