The addconfigurationgroup command can be used to add a group to Corrade's configuration.

llInstantMessage(CORRADE,
    wasKeyValueEncode(
        [
            // Remove a configured group.
            "command", "removeconfigurationgroup",
            "group", wasURLEscape(GROUP),
            "password", wasURLEscape(PASSWORD),
            // The name or the UUID of a group.
            "target", "b2eaaaea-995a-01d3-10eb-712d3b2d68f4",
            "callback", wasURLEscape(URL)
        ]
    )
);

• The group passed to the target parameter can be a name or an UUID but the group has to exist on the connecting grid or Corrade will not find the group.
• When the command is executed, Corrade removes the group from the configuration, the configuration file is updated and then Corrade will reload the configuration. As a consequence, removing a group with this command is permanent since the group configuration will be stored in Corrade's configuration file.
• This command is added out of convenience because pulling the entire configuration (or even just a group configuration) would most likely exceed the 2KiB restriction imposed by http_request. To change individual settings for a group, you should consider accessing the configuration using the configuration command instead of removing and creating the entire group again.
• To add a group dynamically, you would use the addconfigurationgroup command.