If you want to export the code instead the name of a list that is used in a line item, please make use of the 'line items of Data-Type List' tab in the export action. It defaults to Name, you can modify that to code.
I hope you are trying to do the export and you are expecting the code to be displayed in your export file. Hence this option will be available during your export. Else if you want the code in your module, then create a line item (Text formatted) and put a formula 'CODE(List formatted line item)'.