help on creating a CSV file on the fly and sending it over to the customer

Hello everyone, I would like to create a PHP script to do the following : It 's a order system that allows a certain user to select the orders and have the system to write a CSV (a text file of the result query that has fields separated by ;) and then send it over to the user through http. This user is the one that will process the order, not the buyers who are actually entering the orders. 1) Allow this user to select orders by clicking checkboxes. The orders numbers would be presented as a HTML table with checkboxes. Once the user clicks submit it would send through post the order number so that a query could be executed to retrive all order data with the selected order numbers. 2) Once the query is triggered the system would produce a text file on CSV format with the query result an send it over to the user through http. Has anyone ever did something like this? Can anyone help me or give me any directions on how to achieve it? Thank you very much, Carlos Fernando.