OK here is the case

I live in Hong Kong, and I have been playing this game using an NA account

I temporary left this game in 2010 (actually because of the 3D secure payment problem)

Now I am back and ppl told me to buy the 3 abyseea add-ons.

They told me to buy the ultimate abyssea collection because of the super cool hat.

Then I tried all sites selling the NA version of the collection, all of them told me that I can't buy because my IP address is not in US.

Then I keep looking around in the internet. I saw a UK site selling the collection
http://uk.gamesplanet.com.
Without a thought I jump in and try to purchase.

YAY, I can finally buy the game.

I got the code now

when I try to register the code inside POL, it just keep giving me error.

Now I've just downloaded the 4.3Gb.

Can I use my NA account on my freshly installed POL and EU version of FFXI?