This article explains how to add the required ADM or ADMX/ADML files to have them appear in the local GPEDIT policy editor.
The required ADMX/ADML files are located in the WEM download zip file under the "Agent Group Policies" folder. These must be added to either the local PolicyDefinitions folder on a computer, or the same folder on a domain controller or the Group Policy "Central Store", if configuring for utilization in Microsoft Group Policy Management, depending on the Group Policy configuration for the domain.
More information on the specifics of how to perform this operation can be found in Microsoft documentation located in the "Additional Resources" section of this article.
Managing Group Policy ADMX Files Step-by-Step Guide - https://msdn.microsoft.com/en-us/library/bb530196.aspx