Is it possible to add a part to an idw but not the assembly it is derived from?

I am currently putting together a DPD of a through wall lock assembly. i have been asked to show the through wall liner with the drawing however these are two different assembly models and the model that they are both on together is a large one so makeing a new level of detail on that model would be a pain. Basicly what im asking is, is there a way to add a part or another assembly just to a drawing not changing the assembly the drawing is derived from???

P.S - The liner can be added to the through wall lock assembly model becasue it would have too many knock on affects within company.