Guest Script Manager - unable to set Windows IP

I want to set the IP configuration on a Windows 2012 R2 vm, with default settings, like UAC enabled and powershell execution policy RemoteSigned. The account I use for execution is a member of the local admin group. The server is not in a domain.

I have first used the sample scripts provided by the GSM creators. Each time I get the following error, coming from the guest:

[2015-09-14 10:57:36.352] [E] C:\Users\VirtualisierungAdmin\AppData\Local\Temp\vmware74\vco_vmware101.ps1 :
Command EnableStatic failed with exit code 2147749891    + CategoryInfo          : NotSpecified: (:) [Write-Error], WriteErrorExcep   tion    + FullyQualifiedErrorId : Microsoft.PowerShell.Commands.WriteErrorExceptio   n,vco_vmware101.ps1

Setting the execution policy to unrestricted did not help.

I have also created a batch script, which leverages the netsh interface ip set address... command. I ran it directly with "Run Script in Guest". But this method requires an elevated prompt and afaik, without some third party tools, you cannot elevate the command shell yourself, from within it.

Any ideas? Thank you in advance...