Exchange Management Shell - Create Distribution List of External contacts from csv

Anyone got any clue how I can create a distribution group containing lots of external contact email addresses from a csv or such.

Do I need to have them all created as contacts first before adding them to a distributiion list?

I cant see a way to do this through EMC so Im guessing it will need to be done through the shell..

Members of the distribution group can only be those that already exist on the server so you will need to first create them as contacts, yes.

For the powershell command, have you tried this?
Import-Csv contacts.csv | ForEach { New-MailContact -Name $_.displayName -Firstname $_.FirstName -LastName $_.LastName -ExternalEmailAddress $_.EmailNddress -OrganizationalUnit "YourDomain.Local/Contacts" }

Further instructions and advice at My MCP: Bulk importing contacts from CSV to Exchange 2007 and
http://technet.microsoft.com/en-us/l...EXCHG.80).aspx

Assuming it's 2007.