You can export the messages and their translations to PO files. Check locale.pot to get only the messages, without their translations. Check any other option to get a PO file with the messages and their translations to the selected language. Then click the Export button.

You can export the messages and their translations to XLIFF files. Check any option to get a XLIFF file with the messages and their translations to the selected language. Then click the Export button.

You can add new messages and translations importing a PO file. Enter the filename, select the language of the translations and click the Import button.