Upload and validate corporate card transactions - attached receipt files

Summary:

Is there a way in the expense management credit card transactions interface process where we can include additional files (attachments)?

Background: Our creditcard provider has an option to send pictures of the purchase receipt along with the credit card transaction file in a separate file. A feature they call Eurocard Smart Receipt. The receipts are linked to the creditcard transactions via common references. We have already built an integration to import the corporate credit card transactions into the expense management module. Now we would like to enhance this as follows: when the employee creates the expense report lines and selects the credit card transactions we have uploaded, we would like those receipt pictures to automatically show up and be attached