WMI / Powershell - Getting last logged on information

Hello,

I've been working on a lot of scripts lately and I'm having some trouble parsing the data I'm getting.  I have a quite a few machines that are online but with no one logged into them.  I am about to get the information quickly but I'm having a hard time parsing the data properly.  I created a function to write to a log file so we can easily read it.  This is how I'm getting the data. 

$data = @()
$NetLogs = Get-WmiObject Win32_NetworkLoginProfile -computername $PC
 foreach ($NetLog in $NetLogs) {
     if ($NetLog.LastLogon -match "(\d{14})") {
         $row = "" | Select Name,LogonTime
         $row.Name = $NetLog.Name
         $row.LogonTime=[datetime]::ParseExact($matches[0], "yyyyMMddHHmmss", $null)
         $data += $row
     }
 }
$data | Sort LogonTime -Descending | select-object -first 1

 and this is what it outputs:

Name                                    LogonTime
----                                    ---------
AD\ServiceAccount	                8/9/2013 10:17:10 AM

I then wrote a simple function to write a log file so I want it write the log like:

Logwrite "name,logontime"

I've tried a ton of different combinations and I've had no success.  What is the best way to go about this?