Redmine

When I use this:

menu :project_menu, :example, { :controller => 'example', :action => 'say_hello' }, :caption => :label_plugin_example

the menu caption is 'label_plugin_example', which is not the string defined in the plugin's lang file. But if I change the :label_plugin_example to a string defined in the redmine's lang file, it will display the right string.

Can I use a localized menu text for my plugin as the redmine's project menu does?