The best way would be to try and get them scanned as explained here: https://www.lansweeper.com/knowledgebase/viewing-and-scanning-software-license-keys/
However, if that doesn't work due to the restrictions of Office, the best alternative would be to use a custom field. More information on that here: https://www.lansweeper.com/knowledgebase/configuring-and-adding-data-to-asset-custom-fields/
