yeah I got EU and US accounts but you need to download 2 different clients on your PC.you need an EU and US wow acc
Why dont you just launch EU or US first then go into realmlist and change it to the opposite and launch the second window ?
set realmlist eu.logon.worldofwarcraft.com
set patchlist enGB.patch.battle.net:1119/patch
set realmlistbn ""
set portal eu
set realmlist us.logon.worldofwarcraft.com
set patchlist enUS.patch.battle.net:1119/patch
set realmlistbn ""
set portal us