The Product Import Export plugin has the capability to handle data from external third-party plugins. These custom or additional fields generally termed as metadata are created as a result of installing and activating third-party plugins.
Export custom field/data from third-party plugins
In order to export custom field/data from third-party plugins all you have to do is to just check-in the Include hidden metadata field from the export page.
On exporting products by checking in Include hidden metadata field, a CSV file will be downloaded into your system containing all additional metadata fields from your site. The meta fields are appended at the latter end column preceding the default WooCommerce fields. These custom fields can be identified easily with the keyword meta followed by necessary meta keywords as it is in the database depending upon the nature of the third party plugin used.
For more information on how products are exported, see Setting Up Product Import Export Plugin For WooCommerce.
Import custom field data/metadata from third-party plugins
It is to be noted that, the system accepts metadata only in the same formats as it is stored in the database. So the best practice would be to export the data first and then use the exported spreadsheet for importing products. This methodology will help in reducing the compatibility issues considerably.
Once exported, a CSV file in the required format and headers will be generated with custom meta fields. Enter the product details into it and import it back to your store in the usual manner.
To import Products to your store, you must first enter details in the CSV file which is to be uploaded. For more information on how products are imported, see Setting Up Product Import Export Plugin For WooCommerce.