You don't need to define or map the variable in the component, the reference to it in the expression handles all that. You need to find out what it is building as the output of the expression. go into the express designer and click the evaluate and see what it builds, make sure it is building a valid statement. I can't tell you much more. I have provided all the basics to get you there, now you have to make sure what it creates will actually run.

CEWII