Executing Powershell script as different User in Exchange 2007 Powershell - powershell

Question

My scenario looks like this:
Java opens a Powershell in which Exchange Powershell Command/Scripts should be executed as a different user and the output should be displayed in the Powershell windows that Java opened (so Java can read the output).
So: Normal Powershell --> Add Exchange functionality --> Execute Script/Command as different user
To add Exchange functionality to the normal Powershell I use either
add-pssnapin Microsoft.Exchange.Management.PowerShell.Admin or start Powershell like this C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe -PSConsoleFile "C:\Program Files\Microsoft\Exchange Server\bin\exshell.psc1" -command ". 'PathToScript/script1.ps1'"
The problem is the execution as a different user:
runAs (or other tools like PSEXEC or minirunAs) is not working because it opens a new window so the output is not shown in the powershell window opened by Java (an therefore cant be read by Java) and is not suitable for automation
I tried 2 different ways to do it with Powershell:
Way 1:
$username = 'domain\user'
$password = 'Pa$$w0rd'
$cred = New-Object System.Management.Automation.PSCredential -ArgumentList #($username,(ConvertTo-SecureString -String $password -AsPlainText -Force))
Invoke-Command -Credential $cred -ComputerName localhost -FilePath PathToScript/script1.ps1
But i get the following Error:
An Active Directory error 0x80072020 occurred while searching for domain controllers in domain MYDOMAIN: An operations error occurred.
+ CategoryInfo : NotSpecified: (0:Int32) [Get-MailboxStatistics], ADTransientException
A simple whoami works this way an prints the user specified in $username but according to this link it looks like that this is not possible with Exchange command (but I dont know how reliable the source is): http://thwack.solarwinds.com/thread/40524
Way 2 (as suggested here http://social.technet.microsoft.com/Forums/en-US/ITCG/thread/f805cbe0-bca9-401a-a381-a7f5520244d2):
$computerName = "localhost"
$username = 'domain\user'
$password = 'Pa$$w0rd'
$cred = New-Object System.Management.Automation.PSCredential -ArgumentList #($username,(ConvertTo-SecureString -String $password -AsPlainText -Force))
$session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri http://$computerName/powershell -Credential $cred
Import-PSSession $session
But the problem here is that the URI http://$computerName/powershell does not exist (I get WinRM 502 exception) and I dont know how to get a Powershell Virtual Directory on a Server where just the Exchange 2007 Management Tools are installed.
So my questions are: Is there another way to do this? What am I doing wrong in Way 1 & 2 (more how can I add the Powershell VD with Way 2)? Is it possible at all?
I run Java (7 x64) on a WinSrv2012 with Exchange 2007 Management Tools installed. The Exchange Server runs on version 2007. The script is Get-MailboxStatistics -server ExSrv.
This bothers me for nearly a week now so I highly appreciate any help.

Answer 1

I just found out that executing Remote Powershell Commands/Skripts is not supported with Exchange 2007 (http://howexchangeworks.com/2009/11/exchange-2007-sp2-supports-powershell.html). So I need to wait until the upgrade to 2013.
Some workarounds: http://social.technet.microsoft.com/Forums/en-US/exchangesvrgeneral/thread/4596035a-cede-4541-8b8e-e2e9bf1b40dc
Or: http://peerfect.blogspot.co.at/2012/10/re-blog-of-my-exchange-remote.html