If you did not start here then you probably started in the wrong place. If you start with the article I linked to, there's code for creating and...

So you mean you're trying to use something like a parameterized stored procedure as the source for the subreport? Can you give us an example of what you're doing?

Because the default, 80, was being used by another SSRS instance?

You mean this script in the same set of articles?
https://www.mssqltips.com/sqlservertip/1243/auto-generate-sql-server-database-restore-scripts/

Are you talking about NTILE()?
SELECT BusinessEntityID
    , JobTitle
    , NTILE(4) OVER(ORDER BY BusinessEntityID) AS Quartile
    ,NTILE(2) OVER (ORDER BY BusinessEntityID) AS Half
FROM HumanResources.Employee;

Right-click on the RowGroup, then select the Sorting tab from the Group Properties window, and select the field you want to sort by and set it to Descending?

Since you never really explained what you're trying to accomplish, I have no idea.

If you want an answer, please read this article and follow the directions :

When I ran your query, it said it couldn't find the table...
And you never defined what you mean by Margin. Without TotalCost, how do you define Margin?

Okay, Can you post some sample data and expected output? I'm still not clear on what you're trying to do.

Umm... that post you're adding to is SEVENTEEN YEARS old.
How about...
https://sqlwithmanoj.com/tag/bcp-queryout/

Using the above Cross Apply where we have 3 rows coming back, is there a way to tell it to only send only one row instead of three based on...

Is this an Access question or a SQL Server question? I'm asking because SQL Server uses single quotes to delimit text strings and Access uses double quotes. If you're writing...

(Shows how much I understand about FOR XML... is there a good book on the bare necessities you need to understand about XML in SQL Server?)