database function

I have a function as below, which is working fine.

this function excutes a package to get all the column values for a given aid from procurementaction table and is stored in a variable l_pa
i select one of the column like awardnbr and display the value of it

my requirenment is in "l_pa.awardnbr", i want function to take the column name from the input parameter, instead of hardcoding the column name
meaning it should say something like "select l_pa.p_col_name from dual"

how do i do this

create or replace function get_value(p_aid in number, p_col_name in varchar2) return varchar2 is
l_pa procurementaction%ROWTYPE;
b VARCHAR2(500);
begin
l_pa := ina_pkg.get_pa(p_aid);

select l_pa.awardnbr into b from dual;

return b;
end;

Thanks

Research Dynamic SQL and execute immediate statement.