Credit Suisse address in cover letter

Hello everyone,

I'm a newbie here, so I hope someone gets to read this. I am putting the final hand on my cover letter for a summer internship at Credit Suisse in either the Dublin or London office. I have two questions:

• Which address should I use? Zürich HQ, Dublin (1st choice) or London?
• In my first paragraph, should I mention both the Dublin and London office or just one. For now I have something like: "I am writing to express my interest in the Summer Analyst Internship ... of Crédit Suisse’s Dublin or London office."

Cheers