Below a partial of the existing stored procedure before my changes

   CREATE PROCEDURE [dbo].[GetSelectedStoreDetail] 
	@StoreID uniqueidentifier,
	@InvoiceList varchar(650)
   AS
   BEGIN

	-- Declare a table variable and use a UDF to load the variable with invoice numbers from @InvoiceList.
	DECLARE @InvoiceTable table(ItemInt int NOT NULL);
	INSERT @InvoiceTable SELECT ItemInt FROM dbo.function_split_To_Int(@InvoiceList, ',');
	
	SELECT [InvID]
	  ,[StoreID]
	  ,[InvoiceNumber]
	  ,[InvoiceDate]
		.
		.
	FROM InvoiceHeaderView
	WHERE StoreID = @StoreID And InvoiceNumber IN (SELECT ItemInt FROM @InvoiceTable)
	ORDER BY InvoiceNumber;
  END


Below is what I have tried.

   CREATE PROCEDURE [dbo].[GetSelectedStoreDetail] 
	@StoreID uniqueidentifier,
	@InvoiceList varchar(650)
	@SortBy VarChar(100)

   AS
   BEGIN
	DECLARE @SelectStatement nvarchar(4000)

	-- Declare a table variable and use a UDF to load the variable with invoice numbers from @InvoiceList.
	DECLARE @InvoiceTable table(ItemInt int NOT NULL);
	INSERT @InvoiceTable SELECT ItemInt FROM dbo.function_split_To_Int(@InvoiceList, ',');
	
	SET @SelectStatement =  'SELECT [InvID]
	  ,[StoreID]
	  ,[InvoiceNumber]
	  ,[InvoiceDate]
		.
		.

	FROM EDIHeaderAddrView
	WHERE MemberID = ' + @MemberID + ' And ASWDocNum IN (SELECT ItemInt FROM ' + @InvoiceTable + ') ' +
	' ORDER BY ' + @sortBy;
	exec sp_executesql @SelectStatement;
END


I also tried the following

	Declare @CreateTableStatement nvarchar(4000)
	Set @CreateTableStatement = 'DECLARE @InvoiceTable table(ItemInt int NOT NULL);'
	exec sp_executesql @CreateTableStatement, N'@Result varchar(max) out', @InvTable out
	
	Declare @PopulateTableStatement nvarchar(4000)
	set @PopulateTableStatement = 'INSERT ' + @InvTable + 'SELECT ItemInt FROM dbo.function_split_To_Int(@InvoiceList,' +  ''''',''''' + ')';
	exec sp_executesql @PopulateTableStatement, N'@Result varchar(max) out', @InvoiceTable out

I am still getting the same error, must declare the scalar variable @InvTable