title: Environment variables in PowerShell with a dot (.) in the name
body: <p>I know I can access environment variables in PowerShell using <code>$Env</code>. For example, I can access <code>FOO</code> with <code>$Env:FOO</code>.</p>
  
  <p>I can't figure out how to access the environment variable called <code>FOO.BAR</code>.</p>
  
  <p><code>$Env:FOO.BAR</code> doesn't work. How can I access this from within PowerShell?</p>