title: Find and read specific string from config file with Pascal Script in Inno Setup
body: <p>I have quite long config file and I need to extract specific strings from the file. 
  What I want to extract/read is InstallDir for specific number position e.g. for 20540.</p>
  
  <p>I know how to find string in INI or XML, but cannot handle this form of file.</p>
  
  <p>Piece of the file that shows structure:</p>
  
  <pre><code>"212280"
  {
      "InstallDir"        "D:\\XYZ\\stu\\opr"
      "UpdateKBtoDL"      "0"
      "HasAllLocalContent"        "1"
      "UpToDate"      "1"
      "DisableAutoUpdate"     "0"
  }
  "20540"
  {
      "UpdateKBtoDL"      "0"
      "InstallDir"        "C:\\ABC\\def\\ghi"
      "HasAllLocalContent"        "1"
      "UpToDate"      "1"
      "maintenance_time"      "1339663134"
      "DisableAutoUpdate"     "0"
  }
  "4560"
  {
      "UpdateKBtoDL"      "0"
      "HasAllLocalContent"        "0"
      "UpToDate"      "0"
      "InstallDir"        ""
  }
  </code></pre>