Create Miscellaneous Transaction

Hello.

My client has a need: they offer tastings to their customers to promote new products, and a type and source for these events have already been created. However, they need to be able to add a field at the "Transaction Lines" level when Create Miscellaneous Transaction to retrieve customer information. When reviewing the fields at the line level, I can't find any option to retrieve this information.

This is necessary for auditing purposes; with this field, they can generate a complete report of the tasting and the participating customer.

Does anyone know if there's a way to achieve this?