Save preferred user-language on WooCommerce-Checkout using WPML

We are trying to figure out a way on how to save the preferred user-language when a new customer creates their first WooCommerce-order. The website uses the WPML-plugin for multilanguage-support. In addition to that we’re using the “Shop as Client for WooCommerce”-plugin in order to be able to create orders for other people from an existing admin-account.

The WooCommerce-Shop is a part of an event-hosting-company. People can use the shop as a regular online-shop. At the same time there are employees who can post orders for new customers using the said plugin. This is important since we’re tracking the orders that have been placed at a physical location through the WooCommerce-Shop as well.

We are now looking for a way to select and save a preferred language on the checkout-page when placing an order for a new customer. In order to do this we have added an additional select-field with the available languages. Now we just need to find a way to save the selected language to the new user-account in order to make sure that the new customer received the order-emails in the selected language. On top of that it would be helpful if the user would automatically see the website in the selected language after they login for the first time.

Is there a way to save the preferred language when placing an order? Any help would be appreciated. Thanks in advance!