Change Command key to Control on Emacs

private.xml

<root>
  <appdef>
    <appname>emacs</appname>
    <equal>org.gnu.Emacs</equal>
  </appdef>
  <item>
    <name>Command to Control on Emacs</name>
    <appendix>stuff</appendix>
    <identifier>private.command_to_control</identifier>
    <only>emacs</only>
    <autogen>
      __KeyToKey__
      KeyCode::COMMAND_L,
      KeyCode::CONTROL_L
    </autogen>
  </item>
</root>