Payables DFF - Transfer to GL Custom Trigger

We are using Oracle GL and Payables version 11.5.10.1, and have created a DFF in the invoice distribution to match the Journal Lines DFF in GL and now want to pass DFF to the ledger.  We found a document (DOC ID 199403.1) on Metalink dated 01-Aug-2003 that says "can only be transferred via the GL import Form, when loaded into the GL_INTERFACE table via a 'custom trigger'. 

1) Is this this still the case 'have to create a custom trigger', functionality not available?

2) If above true, can someone provide guidance on creating that custom trigger?