Change Titles and Dates in a powershell generated CSV File

I am using powershell to generate a CSV File. I am using Quest ActiveRoles. Not sure if that matters but figured I'd mention it. I am exporting a listing of AD users. Another program is going to ingest this file but there's a few problems. The date field is not formatted correctly. I need to shave off the time from the date. I was told the application requires the header names to be specific values. Is there a way to reformat the headers to be called something different?  The script is below

get-qaduser -SearchRoot "OU=San Diego,OU=domain,DC=domain,DC=com","OU=New York,OU=domain,DC=domain,DC=com" -enabled -SizeLimit 0 -NotMemberOf "Test Accounts","Service Accounts","Hitachi-ID Exclude" | Select Email,FirstName,LastName,Department,WhenCreated  | Export-Csv 'C:\Scripts\Active Directory\InfoSec-UserExport.txt' -NoClobber -NoTypeInformation -Force

The output I get is

"Email","FirstName","LastName","Department","whenCreated"
"User1@domain.com","UserF1","UserL1l","Cashiering","9/8/2006 11:33:53 AM"
"User2@domain.com","UserF2","UserL2l","Cashiering","9/13/2006 11:50:59 AM"
"User3@domain.com","UserF3","UserL3l","Cashiering","12/6/2012 2:51:43 PM"


In the "When Created" field, I need to shave off the time and just include the date MM/DD/YYYY.

these titles need to change from:
"Email","FirstName","LastName","Department","whenCreated"
To:
"emailAddress","firstName","lastName","Department","whenCreated"


I'm assuming I need to do an import-csv but not sure exactly how to go about editing a particular field in a CSV in each record and also modify the column headers :(



Thank you in advance!