The PolicyFileEditor module allows you to modify the contents of registry.pol and gpt.ini files
   in local GPOs. These .pol files correspond to the settings found under Administrative Templates
   in the Group Policy Object Editor console. However, you need to know which registry values need
   to be modified in order to affect a particular Administrative Templates setting.

   To find this information, you can either search online, or, if you're running a Windows Vista/2008
   or later system, you can examine the contents of the .adml and .admx files found in the directory
   <SystemRoot>\PolicyDefinitions. This is how the Group Policy Object Editor console determines what
   settings to display in its console, and how to read or set the values in the registry.pol files.

   The first thing you should do is search the .ADML files in the language directory of your choice.
   If your language is US English, you'd search the files in the PolicyDefinitions\en-US directory.
   Inside these files, you'll find the exact strings that are displayed in the Group Policy Object
   Editor console for each setting.

   For example, if you want to know how to modify the "Limit maximum display resolution" setting
   for Remote Desktop Services, when you search the folder, you'll find this line in the
   TerminalServer.ADML file: <string id="TS_MAXDISPLAYRES">Limit maximum display resolution</string>.

   Next, open the associated .ADMX file (in this case, TerminalServer.ADMX) from <SystemRoot>\PolicyDefinitions,
   and search for the string ID you found in the ADML file (in this case, TS_MAXDISPLAYRES). You'll find a <policy>
   element associated with that displayName. In this case, it looks like this:

    <policy name="TS_MAXDISPLAYRES" class="Machine" displayName="$(string.TS_MAXDISPLAYRES)" explainText="$(string.TS_MAXDISPLAYRES_EXPLAIN)" presentation="$(presentation.TS_MAXDISPLAYRES)" key="SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services">
      <parentCategory ref="TS_SESSIONS" />
      <supportedOn ref="windows:SUPPORTED_Windows7" />
        <decimal id="TS_DisplayRes_Width" valueName="MaxXResolution" minValue="640" maxValue="8192" required="true"/>
        <decimal id="TS_DisplayRes_Height" valueName="MaxYResolution" minValue="480" maxValue="8192" required="true"/>

   Not all Policy elements are this simple. Sometimes they can have different actions for Enabled / Disabled, and so on.
   You can learn more about ADMX file syntax at https://technet.microsoft.com/en-ca/library/cc753471(v=ws.10).aspx .

   In this case, you can see that two registry values are being modified, named MaxXResolution and MaxYResolution
   (indicated by the valueName attributes on the two <decimal> elements). A <decimal> element indicates that the
   data type will be DWord.

   Armed with that information, you can now do something like this using the PolicyFileEditor module:

   $entries = @(
       New-Object psobject -Property @{ ValueName = 'MaxXResolution'; Data = 1680 }
       New-Object psobject -Property @{ ValueName = 'MaxYResolution'; Data = 1050 }

   $entries | Set-PolicyFileEntry -Path $env:SystemRoot\system32\GroupPolicy\Machine\registry.pol `
                                  -Key 'SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services' `
                                  -Type DWord