Issue populating DFF data using the Open Payables Interface...Help Please

Hello all you experts.......

We are currently on R12.1 and we are trying to use the Open Payables Interface to load data into our AP Application.  The issue that we are currently experiencing is that we have a custom DFF in the Invoice Distributions Form and we can't find a way to load this data using the Open Payables Interface since it appears that data can only be loaded into the AP_Invoice_Lines_All Table.  Does anyone know a way of loading this DFF data direclty into the AP_Invoice_Distributions_All Table using the Open Payables Interface??  See screenshots.....