How can I sort PSObjects and remove duplicates with the oldest date?

Hi,

I have a collection of PSObjects which contains several values. My goal is to produce a list of unique AppToken objects but the kicker is if a duplicate object exists, I need to keep the newest one (which can be determined by dtCreatedDate)

Here's what I have tried (Unsuccessfully)

$tokenTable = $tokenTable|sort-object -property @{Expression="dtCreatedDate";Descending=$true}

$tokenTable = $tokenTable|sort-object -property @{Expression="AppToken";Descending=$true} |get-unique -asstring

I can get the commands to work individually, but not together.

I also tried a one liner:

$tokenTable = $tokenTable|sort-object -property@{Expression="AppToken";Descending=$true},@{Expression="dtCreatedDate";Descending=$false}|get-unique -asstring

Here's what the object looks like:

TypeName: Selected.System.Management.Automation.PSCustomObject

Name                   MemberType   Definition                                        
----                   ----------   ----------                                        
Equals                 Method       bool Equals(System.Object obj)                    
GetHashCode            Method       int GetHashCode()                                 
GetType                Method       type GetType()                                    
ToString               Method       string ToString()                                 
ApplicationDisplayName NoteProperty System.String ApplicationDisplayName=website       
AppToken    NoteProperty System.String AppToken=/dty            
DatabaseName           NoteProperty System.String DatabaseName=DB1         
DBServer               NoteProperty System.String DBServer=DBSQL1
dtCreatedDate          NoteProperty System.DateTime dtCreatedDate=10/03/11 6:24:13 AM 
isCustom   NoteProperty System.Boolean isCustom=False         
IsEnabled              NoteProperty System.Boolean IsEnabled=False