Limiting results and using a dynamic column name??

[denevge]

You will have to user native dynamic SQL.
Something like this ( example taken from oracle docs )

Examples of Dynamic SQL for Records, Objects, and Collections
As the following example shows, you can fetch rows from the result set of a dynamic multi-row query into a record:

DECLARE
TYPE EmpCurTyp IS REF CURSOR;
emp_cv EmpCurTyp;
emp_rec emp%ROWTYPE;
sql_stmt VARCHAR2(200);
my_job VARCHAR2(15) := 'CLERK';
BEGIN
sql_stmt := 'SELECT * FROM emp WHERE job = :j';

OPEN emp_cv FOR sql_stmt USING my_job;
LOOP
FETCH emp_cv INTO emp_rec;
EXIT WHEN emp_cv%NOTFOUND;
-- process record
END LOOP;
CLOSE emp_cv;
END;