I'm sure I used to be able to successfully use the Display command  "paste onto background" to paste a  picture of a selected object onto my background pic and then render and see the result. This option let you build up a picture by adding the renders of objects instead of many actual objects

At the moment the bitmap of this object is only visible in Preview mode and is not there when the scene is rendered.
I can "paste into background" perfectly Ok in Preview mode but a render will destroy them..

Hope I'm clear enough for you all on this..

I've tried all variations of choices ! With and without first having a background pic, then choosing various options under Render Over. And Render option variables..I think I've tried it all...

Any hints?