Dynamically defining a Table Function's structure

I'm attempting to dynamically define a table function using a value entered by the user. My Oracle version 11.2.0.1

I'm using the ODCITableDescribe, ODCITablePrepare, ODCITableStart, etc interface functions as described in the documentation.

As seen in the documentation for ODCITableDescribe:

"Any arguments of the table function that are not constants are passed to ODCITableDescribe as NULLs because their values are not known at compile time.".

I'm calling the table function as: select * from table(CommsPortLevelObj.do('MyNode'));   where I expect 'MyNode' to be a constant that is passed as a parameter to the ODCITableDescribe and ODCITablePrepare functions as is so I can dynamically create the structure of the table. Unfortunately, the argument is always NULL which prevents me from defining the structure.