How do I use a new line character using powershell for a registry value?

New-ItemProperty -Path HKLM:\SYSTEM\ControlSet001\services\WebClient\Parameters -Name AuthForwardServerList -PropertyType MultiString -Value "http:\\test.com'r'nhttps:\\test.com"

Above is the code that I'm trying to use to create a new registry value, with http:\\test.com and https:\\test.com on separate lines (because the Multistring type takes values on separate lines.  However, the result from this script is all of that text on one line, even including the 'r and 'n.  So the result is http:\\test.com'r'nhttps:\\test.com.  The output should look like this:

http:\\test.com
https:\\test.com

I can't even get this to work using Write-Host.  Am I even using the correct syntax with the 'r'n?  I can't seem to find anything on the Internets regarding new line characters for PowerShell.