thats really tricky, not only putting any extra view on top, also to receive events.
I had to put a table view above the buttons. Though I could use a xib to make a view like actions sheet and animate up.
anyway, to put any image or view above the buttons and receive events, add that view to the actionsheet's superview. Like :
df.frame = CGRectMake(0, 0, 320, 200);
[[actionSheet superview] addSubview:df];
[[actionSheet superview] sendSubviewToBack:df];
Hope it helps