Script logic: how to create a variable on SAP BPC

Here the select condition to insert in a SAP BPC script logic in order to create a dynamic variable:
 
*SELECT(%REPORTING_CURRENCIES%, “ID”, “CURRENCY”, “[GROUP] = 'REP'”)    

• %REPORTING_CURRENCIES% is the name of our variable
• ID is the column that indicate our result
• Currency is the name of the dimension
• Group='REP' is the property to use in that selection