The second step of the export wizard is the Field Mapping where you can connect the product details in your store to your new export file's headers.
Please note that you won't be able to modify the Syncee Supplier Exchange, Google Merchant, Facebook product catalog and Shopify Export file structures, as they already have the exact format that those platforms need.
If you would like to request any change with their structure, you can contact the support staff for help.
However, you can customize tha RAW and FLAT file structures as you wish.
All you need to do is to select the adequate field from the drop-down box. You can add more values by clicking on the + icon.