The procedure will first need to run a query on the table, then run a fetch statement to retrieve the values of the two columns from the query results.

Below is a sample procedure that does this. It runs a query on a table  named Customers, and then runs a fetch to retrieve the values of columns CompanyName and City from the query results. It stores the values in variables called 'name' and 'city'.

PROCEDURE pReadTwoColumns()
BEGIN
declare result cursor;
declare name VARCHAR(100);
declare city VARCHAR(100);

OPEN result FOR SELECT CompanyName, City from /shared/examples/ds_orders/tutorial/Customers;

fetch result into name, city;   
    whileloop:
    while result.found
       do
          begin
             fetch result into name, city;
             CALL PRINT ('The company name is : ' ||  name || ' and the city is : ' ||  city );
          end;
       end while;
    close result;
END

The Studio Console displays the following output:

The company name is : Anston Systems and the city is : Burlingame
The company name is : Blackard Electronics and the city is : San Mateo
The company name is : Connect Software and the city is : Philadelphia
The company name is : Canal Street Solutions and the city is : Reading