IDoc Segment Additions in Class

I am working on logic in a BAdI implementation of MDM_BUPA_INBOUND with a filter on message type ADRMAS.  Basically I need to add some extra E1BPAD1VL segments before the address processes.

I am pulling international version address records from the ADRC table so they can be included with the default addresses I have coming from another system.  I have the ADRC data populated in an internal table (it_adrc) but am not able to get append or insert working for getting the records added to idoc_data. 

I will continue searching for examples, but any suggestions on what I need at the end of this code to get my new st_e1bpad1vl structures into the IDoc?I am new to working with classes/methods in "OO ABAP" arena.

Thanks in advance,

Keith