Código SQL:
Ver original(
SELECT COUNT(tbl_lideres.Valores_Cod) AS Expr1, tbl_lideres.Valores_Cod
FROM tbl_lideres RIGHT OUTER JOIN
tbl_ganar ON tbl_lideres.Cod_Lider = tbl_ganar.Cod_lider
WHERE (tbl_lideres.Country = @Country) AND (tbl_lideres.State = @State) AND (tbl_lideres.City = @City) AND (tbl_lideres.RED = @Red)
GROUP BY tbl_lideres.Valores_Cod
)UNION(
SELECT 0 AS Expr1,tbl_lideres.Valores_Cod
FROM tbl_lideres b
WHERE (b.Country = @Country) AND (b.State = @State) AND (b.City = @City) AND (b.RED = @Red) AND
b.Cod_lider NOT IN
(
SELECT g2.Cod_lider
FROM tbl_ganar g2
)
)
Tal vez sea un poco más lento que otras opciones, pero es efectivo.