SQL - variables de consulta en subconsultas

DECLARE @Sdt_FecPag SMALLDATETIME

DECLARE @P_NumCre INT

set @Sdt_FecPag = '01/01/1900'

SET @P_NumCre = 130058

declare @crefechgeneinte smalldatetime

SELECT

c.crenumero

, c.crefechgeneinte

, isnull(pp3.Ti_UltCuoVen, 0) as Ti_UltCuoVen

, case isnull(pp3.Ti_UltCuoVen, 0) when 0 then c.crefechgeneinte else pp3.Sdt_FecUltCuoVen end as Sdt_FecUltCuoVen

, dia.D_IntCorCS

FROM

dbo.vistintecorr as c

left outer join (

SELECT

ppcuota as Ti_UltCuoVen

, ppfecha as Sdt_FecUltCuoVen

, crenumero

FROM

dbo.planpago

WHERE

ppfecha <= @Sdt_FecPag

AND ppcuota = (

SELECT MAX(ppcuota) FROM planpago as ppn

WHERE ppn.crenumero = dbo.planpago.crenumero

AND ppfecha <= @Sdt_FecPag

)

) as pp3 on pp3.crenumero = c.crenumero

left outer join (

SELECT SUM(diavalointe - diaabonsubs) as D_IntCorCS, crenumero

FROM dbo.diario

WHERE diaestado = 'CS'

AND diafecha < (select case isnull(Ti_UltCuoVen, 0) when 0 then c.crefechgeneinte else pp.ppfecha end as ppfecha

FROM planpago as pp

WHERE pp.crenumero=dbo.diario.crenumero and

pp.ppfecha <= @Sdt_FecPag

AND pp.ppcuota = (

SELECT MAX(pp2.ppcuota) FROM planpago as pp2

WHERE pp2.crenumero = dbo.diario.crenumero

AND pp2.ppfecha <= @Sdt_FecPag

))

group by crenumero

) as dia on dia.crenumero = c.crenumero

WHERE c.crenumero = @P_NumCre

ORDER BY c.crenumero