KeyRemap4MacBook config file to make the backslash available in my keyboard from USA (using SPANISH_ISO in OSX).

private.xml

<?xml version="1.0"?>
<root>
  <item>
    <name>get_backslash_spanish_keyboard</name>
    <inputmodedetail_only>SPANISH_ISO</inputmodedetail_only>
    <identifier>private.get_backslash_spanish_keyboard</identifier>
      <autogen>--KeyToKey-- KeyCode::SPANISH_LESS_THAN, ModifierFlag::OPTION_R, KeyCode::SPANISH_ORDINAL_INDICATOR, ModifierFlag::OPTION_R</autogen>
  </item>
</root