hot to add a static value to PRD prompts

we need to add a row to the return set of a MQL query, used to populate a parameter drop down.


eg:


MQL query returns:


EUROPE
ASIA
AMERICA
AUSTRALIA
AFRICA


Drop down must be populated with values:


ALL VALUES <------------------
EUROPE
ASIA
AMERICA
AUSTRALIA
AFRICA


direct SQL cannot be used in this context because we have to use metadata to take into consideration also user rights and data visibility.


Is there a viable way to implement this?


Thank you
Virgilio