You’d need to write a bit of Python (or something) to connect to the live database, read the import data, match to the WP topic, then update the “date created” field (whatever that is exactly… “post publish date” ?) in WP and update it with the value you want from the loaded data.
If you look in the live WP database and find the post ID of the first post of your loaded data you can match each post sequentially in order to update it.