Pivot table with case when condition error.

Msg 207, Level 16, State 1, Line 7
Invalid column name 'CL'.
Msg 207, Level 16, State 1, Line 13
Invalid column name 'H'.
Msg 207, Level 16, State 1, Line 15
Invalid column name 'A'.
Msg 207, Level 16, State 1, Line 15
Invalid column name 'P'.

ALTER Procedure [dbo].[Pivot_Attendance2]


As  
Begin 

SELECT DISTINCT ReportingDate INTO #Dates
FROM EmployeesAttendance

ORDER BY ReportingDate

DECLARE @cols NVARCHAR(4000)
SELECT  @cols = COALESCE(@cols + ',[' + CONVERT(varchar, DATEPART(DAY, ReportingDate), 112)
				+ ']','[' + CONVERT(varchar,DATEPART(DAY, ReportingDate), 112) + ']')
FROM    #Dates
ORDER BY ReportingDate


-- Building the query with dynamic dates
--DECLARE @qry NVARCHAR(4000)
--SET @qry =
--'SELECT * FROM
--(SELECT EmpID, Status , ReportingDate
--FROM EmployeesAttendance)emp
--PIVOT (MAX(Status) FOR ReportingDate IN (' + @cols + ')) AS stat'

DECLARE  @qry NVARCHAR(4000) =
N'SELECT * 
FROM (SELECT     EmpID, ReportingDate, CASE WHEN [Days] IS null AND EXISTS
                          (SELECT     1
                            FROM          EmpApplication
                            WHERE      EmployeesAttendance.Empid = EmpApplication.Empid AND 
                            (ReportingDate >= LeavFrom AND ReportingDate <= LeavTo))
                             THEN CL
                             WHEN [Days] IS null AND
                       EXISTS
                          (SELECT     1
                            FROM          Holidays
                            WHERE      ReportingDate = HolidayDate) 
                            THEN H 
                                                        
                            WHEN [Days] IS null THEN A WHEN [Days] = 1 THEN P END AS Status,

DATEPART(DAY, EmployeesAttendance.ReportingDate)as DDate

FROM EmployeesAttendance  )emp
PIVOT (MAX(Status) FOR DDate IN (' + @cols + ')) AS stat 
'
-- Executing the query

EXEC(@qry)
 
END