MS SQL, outer column in sub-query - sql-server

Question

giving this table definitions:
CREATE TABLE Attivita_T041(Kint_TP013_IdAttivita INT)
CREATE TABLE TP004_LinkPersonaArea
(int_T013_IdArea int,
dte_T013_DataInizio date,
dte_T013_DataFine date,
int_T013_IdPersona int,
int_T013_IdRuoloArea int)
go
CREATE TABLE [dbo].[Q_TP013_Pianificazione] (
[Kint_TP013_IdAttivita] INT ,
[Ksin_TP013_IdArea] SMALLINT,
[Ksin_TP013_AnnoRifPian] SMALLINT,
[sin_TP013_Giorni] SMALLINT
);
i need a table function with a query that join Attivita_T041 table with many others and now i have to add a subquery to get two information: total of [sin_TP013_Giorni] and total of [sin_TP013_Giorni] for [Ksin_TP013_IdArea] where current user actualy work in (reading from TP004_LinkPersonaArea)
that is this part of the query:
SELECT ....
FROM Attivita_T041
INNER JOIN ---- many other tables here
LEFT OUTER JOIN PersonaArea_T013
ON int_T013_IdPersona = #idUtente
AND dte_T013_DataInizio <= #dataRiferimento
AND (dte_T013_DataFine > #dataRiferimento OR dte_T013_DataFine IS NULL)
LEFT OUTER JOIN (
SELECT
Kint_TP013_IdAttivita
, SUM(sin_TP013_Giorni) AS GiorniPianificatiAnno
, SUM(CASE
WHEN Ksin_TP013_IdArea = int_T013_IdArea THEN sin_TP013_Giorni
ELSE 0
END) AS GiorniPianificatiAnnoArea
FROM
Q_TP013_Pianificazione
INNER JOIN dbo.FN_DettaglioPianificazione(YEAR(#dataRiferimento), 0)
ON Progressivo = Ktyi_TP013_ProgressivoPian
WHERE
Ksin_TP013_AnnoRifPian = YEAR(#dataRiferimento)
GROUP BY Kint_TP013_IdAttivita
) AS Pianificazione
ON Kint_TP013_IdAttivita = Kint_T041_IdAttivita
but i can't do that because int_T013_IdArea column i nedd is outer of subquery
searching on SO i find the suggestion to use OUTER APPLY so i switch to this:
OUTER APPLY (
SELECT TOP 1
SUM(sin_TP013_Giorni) AS GiorniPianificatiAnno
, SUM(CASE
WHEN Ksin_TP013_IdArea = int_T013_IdArea THEN sin_TP013_Giorni
ELSE 0
END) AS GiorniPianificatiAnnoArea
FROM
Q_TP013_Pianificazione
INNER JOIN dbo.FN_DettaglioPianificazione(YEAR(#dataRiferimento), 0)
ON Progressivo = Ktyi_TP013_ProgressivoPian
WHERE
Ksin_TP013_AnnoRifPian = YEAR(#dataRiferimento)
AND Kint_TP013_IdAttivita = Kint_T041_IdAttivita
) AS Pianificazione
but now i get this error:
Multiple columns are specified in an aggregated expression containing
an outer reference. If an expression being aggregated contains an
outer reference, then that outer reference must be the only column
referenced in the expression.
is there a way to do that?