Mass update Company Account Name in Manage Corporate Cards

We are importing new corporate cards for users from a new provider. The cards imported without issue with the new setup, but did not automatically assign to the employee. In the Manage Corporate Cards screen, I can select the card and choose the Company Account Name manually (only one option), and then running validation matches it up correctly. Is there some setup that will pick the Company Account Name Automatically, or where we can easily update the imported values with that field? It will save us time needing to manually update 1800 records. Thanks!