Re: I do NOT want to include code in the main program, I want to load it at runtime

You don't seem to require the ability to load third-party .OBJs, so you might be better off just to pick a style convention for your assembler source that makes it easy to assemble into CALL ABSOLUTE-friendly format (tiny memory model, assembled with `nasm -f bin`). If you are writing all of the code you are trying to load, .OBJ seems like an unnecessary middleman, IMO.