When you use the Table of Contents button on the References tab, what text does word use to generate the table of contents?

Universal containers(us) has an integration with its accounting system that creates tens of thousands of orders inside salesforce in a nightly batch. us wants to add automation that can attempt to match leads and contacts to these orders using the email address field on the insert. us is concerned about the performance of the automation with a large data volume. which tool should uc use to automate this process?