Take PowerShell Output and use for error handling

Hello.

I'm executing a script on a remote PowerShell host, and I want to be able to act upon either the exit code or some other output text within a string variable to do something like log, or fail the workflow within vRO.

The example being that if i attempt to run a native windows command (e.g. dnscmd.exe) within my PowerShell script that returns "Access Denied" or similar, as the PowerShell script still completes successfully, so does the vRO workflow.

How can I forcibly fail the workflow when certain output criteria is met?

Thanks,

Dan