John Fenz Jun 8, 2009:

The difference between oral and written address Indeed. I missed the distinction, and it would also appear to be determinative - if we're comfortable relying on Wikipedia. ;-)

If this is an oral presentation, and it certainly looks like it, "Your Excellency" is the correct translation.

Kim Metzger Jun 8, 2009:

John Consider the difference between written and oral address. The asker's text looks like a speech.

His Most Reverend Excellency (abbreviation Most Rev. Ex., oral address Your Excellency) - The Apostolic Nuncio, because his rank is equal to an extraordinary and plenipotentiary ambassador and he is simultaneously a higher prelate.
http://www.answers.com/topic/self-styled

John Fenz Jun 8, 2009:

Hochwürdigste? Are we just dropping "Hochwürdigste" from consideration? I don't mean to say that "Hochwürdigste Exzellenz" might not be used as a form of address for a person holding a non-religious office - for all I know this is possible. However, if the person addressed IS in fact an Apostolic Nuncio, then - judging from the Wikipedia entry we're both relying on - "Most Reverend Excellency" would appear to be the only way to go.

Kim Metzger Jun 8, 2009:

Novák I just discovered your question buried in the headline. That's confusing. It's better to state the question in the explanation box.

Kim Metzger Jun 8, 2009:

Can you tell us where the Hochwürdigste Exzellenz comes from and what office he holds?