Thank you for your reply.
You can update your meta-titles using MultiEditior or during import. You need to use CONCAT command to merge values.
Please check the following articles for details how to create correct expression that allows to update meta-titles as you need:
http://www.mag-manager.com/useful-articles/tipstricks/how-to-input-missing-data-and-modify-existing-on-the-fly-by-means-of-expressions-in-the-process-of-magento-import
You can also find example of correct expression at Multi Editor - see attached
If you want us to create specific expression or SQL statement for you, please contact us via e-mail and we will provide you with estimated time and cost.
Waiting to hear from you