If you are using eCart with a database and choose to manage the orders in the checkout wizard you will have orders and their details stored for you in your corresponding tables in your db. Once this information is in your db you can view it or edit it directly or you can create an administrative area for you site to view this information. Creating this administration area would require the use of DataAssist.
Exporting the information or integrating it with Quickbooks is not a supported feature of eCart and would require you to create your own custom solution for this.