Entering a GW serial could change my territory?

I am from America but I like more play at Europe server, if I (playing at Europe) enter a Nightfall serial key (of retail product) bought in America will change my territory to America? I've heard rumors about that.

When you enter a key, you create an account. You may select your territory when create your account and can change it FOUR times. It shouldn't matter where you buy your game.

I already have an account (Prophecies/Faction), I am not creating a new one. At the other hand, the option of select territory wasn't available when I created my account 9 months ago, so I lost one change for that; That option is new.

So, my question is: If I ADD a serial to my account, could it change my territory?

(sorry double post)

It shouldn't. I was put into wrong territory after purchasing new account, but the territory didn't change after I added Factions, although it should if it were same as with new account.