title: string variable not substituted in multi-line string
body: <p>Here is the code/output all in one:</p>
  
  <pre><code>PS C:\code\misc&gt; cat .\test.ps1; echo ----; .\test.ps1
  $user="arun"
  $password="1234*"
  $jsonStr = @"
  {
          "proxy": "http://$user:$password@org.proxy.com:80",
          "https-proxy": "http://$user:$password@org.proxy.com:80"
  }
  "@
  del out.txt
  echo $jsonStr &gt;&gt; out.txt
  cat out.txt
  ----
  {
          "proxy": "http://1234*@org.proxy.com:80",
          "https-proxy": "http://1234*@org.proxy.com:80"
  }
  </code></pre>
  
  <p>Content of string variable <code>$user</code> is not substituted in <code>$jsonStr</code>.</p>
  
  <p>What is the correct way to substitute it?</p>