Extra links in books

[Madeleine]

Please could you let me know if it would be a simple thing to add an extra link to the books?  My client sells on both Amazon UK and Amazon US and would like to have a second link under the first.  I can add a column to the MySQL database but my knowledge of PHP is not up to figuring out which code to duplicate to make sure that it appears in both the admin and the front end of the site.
Thanks for the great catalogue by the way.

[federica]

Dear Madeleine,
if you need a customization you have to send a private email. I will be happy to send to you an economic evaluation.

[Madeleine]

Hi Frederica, my client has decided to just use the one link for now.  I'll be in touch if they should change their mind. Thanks