Android : Add header view and push content down

I'm trying to prepend a view(LinearLayout) to an activity View at the top most part of screen, and pushing existing content down. I would like to do it transparently, i.e., pretending that I have no knowledge of exisitng view. I do have ApplicationContext with me.

First, it it even possible? Second, can you please help me in this. I've tried a lot, but nothing seems to work. I'm able to add view to top, but unable to PUSH existing content down.

Thanks in advance...