How to get Errors in an external file

Hi, I am trying to get error messages out of a script into an external file

For example:

New-Item d:\ -Name $Eingabe -type directory | Out-File -FilePath $Logfile 
-Append
$? | Out-File -FilePath $Logfile -Append

I am getting the results out of $? (true) in an file, but I want an extra 
file for every false message.

Is there something like an error level in PowerShell?

Greetz
-- 

# append error messages to a file
New-Item d:\ -Name $Eingabe -type directory 2>> $errFile

# PowerShell has an automatic variable that contains last
# executed legacy apps' exit code:
cmd /c exit 99
$lastExitCode

# for more on Redirection operators:
help about_operator

# for more on Automatic variables:
help about_Automatic_variables

-- 
Kiron