It is currently not possible to transfer one's gold to a dual when you are not the account holder. At the lobby level, it is not considered as an "active world".
I can understand Travian does not want / cannot offer the possibility to buy gold directly from the lobby (I see it as a way to maximize their revenues, but that's ok).
Nevertheless, not being able to transfer gold to an account when you can actually buy gold from this account is a problem and is not "fair".
Would it be possible to change this ?