Stored Procedure-Dynamic column generation while pivot

Hi Team,

I have created stored procedure which transforms rows to columns dynamically using Pivot function and stuff/statement operation in MS-SQL. I have generated the SQL code and I got expected output in DB which dynamically created list of columns. But the problem is when I am using executestoredprocedure function in Appian, the columns which dynamically gets created is missing. 

I tried converting the type in DB but no luck.

I cannot pass selected(hard coded) column values in for() of PIVOT function as my generating column values would be huge.

Help me out..

Thanks in advance,

Melwyn J