unitTag or DisplayName

[Carter_DC]

Hi guys, i got a list of guildmates (displayName and CharName) and trying to get a zoneName for each of them.

Since the only way i know of getting an area name is the GetUnitZone(unitTag),
is there a way to go from a displayName (@accountName) to a unitTag ?

or any other way to get the areaName for theses only 2 vars i got ?

(btw, are zoneNames already localized ? )