From LimeSurvey Manual

 Hint: This features is available starting in version 4.0.1

Add QCODE.question for question with sub-question (array, multiple choice ...) for Expression Script.

For example without this plugin : QCODE_SQ01.question show the text of subquestion SQ01 of question QCODE. But QCODE.question return an error because QCODE are not a related to a answer in survey. With this plugin QCODE return the question text of QCODE.

  Before using these functions : the plugin must be activated in Plugin Manager.