Você quer que a opção "-noClobber" seja exibida no ExportCSV.
Eu também fiz uma solução alternativa que pode funcionar:
# Get the list of computer names from AD
$objDomain = New-Object System.DirectoryServices.DirectoryEntry
$objSearcher = New-Object System.DirectoryServices.DirectorySearcher
$objSearcher.SearchRoot = $objDomain
$objSearcher.CacheResults = -1
$objSearcher.PageSize = 5000
$objSearcher.SizeLimit = 5000
$objSearcher.PropertiesToLoad.Add("name")
$objSearcher.Filter = ("(&(operatingSystemVersion=5*)(objectCategory=computer)(operatingSystem=Windows XP*))")
$output = @()
# for each computer, use WMI to scan for printers
foreach ($objComputer in $objSearcher.FindAll())
{
$output += get-WmiObject -class "win32_printer" -computername $objComputer.Properties.name | ft systemName, name, shareName, Local -auto
}
Export-CSV "c:\printers.csv" -inputObject $output