New-MailConact | I don't have a display name, how can I have the script use the last,first name to generate one?

Import-Csv 'addr.csv' | `
	ForEach{
		New-MailContact $_.dname `
		-DisplayName $_.dname `
		-FirstName $_.fname `
		-LastName $_.lname `
		-organizationalunit "Users/Contacts" `
		-Alias $_.alias `
		-ExternalEmailAddress $_.email
	}
That would work; but I don't have a display name for the users in the CSV file.
Does anyone know how I'd combine the $._lanme with the $_.fname to create a display name of last,first?
Thanks!