$user = "domainservice.account"
$pwd1 = "big long huge string of characters"
$pwd = ($pwd1 | ConvertTo-SecureString)
$Credential = New-Object System.Management.Automation.PSCredential $user, $pwd
$args = "\domain.locallocationlocationlocationScriptscript.ps1"
Start-Process powershell.exe -Credential $Credential -ArgumentList ("-file $args")

start powershell -credential ""

$username = 'user'
$password = 'password'

$securePassword = ConvertTo-SecureString $password -AsPlainText -Force
$credential = New-Object System.Management.Automation.PSCredential $username, $securePassword
Start-Process Notepad.exe -Credential $credential

Start-Process powershell.exe -Credential $Credential -Verb RunAs -ArgumentList ("-file $args")