How I can to set attributes from Delimited Text Driver to Auxiliary Class

Hi

We have a auxiliary class for User Class to store specific data from users.

We have a Delimited Text Driver  for create users and extend the user bject with the auxiliary class, its work fine.

Now, we need other  Delimited Text Driver for store aditional data into Auxiliary class's attributes.

But, when we create the Delimited Text Driver, in the Filter Editor we can't select the Auxiliary class because don't show it.

Then, when run the driver, the users are created fine, but any custom attribute inherited from auxiliary class was update because in the driver log file show 

Filtered out <add-attr attr-name='CustFirstName'>.

How I can update the extended attributes?

Best,