NHF – new heroes for Heroes V 3.1.

Well, it's even simpler than that.

Towns = array of towns;
xyzHero = hero's coordinates;
TargetTown = nil;
MinDistance = 999;
For i, town in towns
Distance = (xyzTown - xyzHero);
If Distance < MinDistance then
MinDistance = Distance
TargetTown = Town
End
End

That's the whole code; all that's left is to translate it from "Olbanian."

This version is better. Otherwise, I'm traveling from Moscow to St. Petersburg via Cape Town.
I probably don't know "Olbanian" very well, but the translation into Lua should be decent.:)

function FindClosestEnemyTown()
	local towns = GetObjectNamesByType('TOWN');
	if IsHeroAlive('Avran') then
		if GetHeroTown('Avran') then
			return nil;
		end;
	else
		return nil;
	end;
	local hx, hy, hz = GetObjectPosition('Avran');
	local dist = {};
	for i, town in towns do
		local tx, ty, tz = GetObjectPosition(town);
		if tz == hz then
			local s = sqrt((tx - hx) * (tx - hx) + (ty - hy) * (ty - hy));
			dist[town] = s;
		end;
	end;
	local targetTown = min(dist);
	if GetObjectOwner(targetTown) == GetObjectOwner('Avran') then
		return nil;
	else
		return targetTown;
	end;
end;