Need to resolve error when customizing NDR messages?

[PS] C:\Windows\system32>Get-SystemMessage -original | where {$_.DsnCode -eq "5.
1.2" -and
>> $_.language -eq "en"} | FL
>>


Text              : The recipient's e-mail address is invalid. Microsoft Exchan
                    ge will not try to redeliver this message for you. Please c
                    heck the recipient's e-mail address and try resending this
                    message, or provide the following diagnostic text to your s
                    ystem administrator.
Internal          : True
Language          : en
DsnCode           : 5.1.2
QuotaMessageType  :
AdminDisplayName  :
ExchangeVersion   : 0.1 (8.0.535.0)
Name              :
DistinguishedName : CN=5.1.2,CN=internal,CN=9,CN=Dsn Customization,CN=Transport
                     Settings,CN=Domain,CN=Microsoft Exchange,CN=Services,CN=Confi
                    guration,DC=Domain.com
Identity          : en\internal\5.1.2
Guid              : 00000000-0000-0000-0000-000000000000
ObjectCategory    :
ObjectClass       : {msExchDSNMessage}
WhenChanged       :
WhenCreated       :
OriginatingServer :
IsValid           : True

I want to change the message with PS but get this error below please advise.

[PS] C:\Windows\system32>Set-SystemMessage En\Internal\5.1.2 -Text "The recipien
t's e-mail address is invalid.  The Email Server cannot redeliver this message f
or you. Please check the recipient's e-mail address and try resending this messa
ge. I you need further assistance please call the help desk."
Set-SystemMessage : The operation could not be performed because object 'En\Int
ernal\5.1.2' could not be found on domain controller 'DCSERVER.Domain.com'.
At line:1 char:18
+ Set-SystemMessage <<<<  En\Internal\5.1.2 -Text "The recipient's e-mail addre
ss is invalid.  The Email Server cannot redeliver this message for you. Please
check the recipient's e-mail address and try resending this message. I you need
 futher assistance please call the help desk."
    + CategoryInfo          : NotSpecified: (0:Int32) [Set-SystemMessage], Man
   agementObjectNotFoundException
    + FullyQualifiedErrorId : 448D9A83,Microsoft.Exchange.Management.Dsn.SetSy
   stemMessage


I need help resolving this error; How can I change the text to ;  " The recipient's e-mail address is invalid.  The Email Server cannot redeliver this message for you. Please check the recipient's e-mail address and try resending this message. I you need further assistance please call the help desk?