SQL Job: Powershell - How to Configure PS?

I have a Powershell script that ages off backup files. It works fine from VS 2012. I'd like to launch it from a SQL Job on the same server but when I do, it throws a series of syntax errors. For instance, one error was that the "-File" option was not recognized by the Get-ChildItem cmdlet. This is odd since the development environment recognizes the option. I'm assuming that the two environments (same server) are using slightly different Powershell versions/environments. How would one configure (or even interrogate) the SQL Agent to use a specific Powershell version?