Positioning an AP div semi-relatively... how?

If I want an AP div (z-indexed to be above the rest of the layout) to be 
positioned 10 pixels higher than the insertion point, what's the best
method 
to achieve this?

The layout is liquid so the distances from the view****t borders are 
unpredictable. That's why I need it very specifically 10px up from the 
insertion point.

Are we talking AP div within a relative div? Or is there a trick with 
negative margins I don't know about?

Thanks.