Allow the scanning of sales invoices

Your company creates sales invoices with an Excel system for calculating numbers and they have many custom fields. He says it's impossible to make the sales invoice in Holded. This is the same case we have with wholesalers who want the packages and kilos in the bill table, for example. So, if the PDF of the sales invoice isn't created in Holded, then we should be able to scan it as expenses and get the main fields.