Excel 2007 : Coloring area in line chart

I created a chart containing several graphs and want to color a certain area underneath a line (while maintaining the other lines if they pass through that area) based on conditions.

Example:
suppose the line has points (1,0) , (3,2), (4,5), (6,0), (1,0)
I want to color the area (3,0), (3,2), (4,5), (5,0) OR both the areas (1,0), (3,2), (3,0), (1,0) and (4,5), (4,0), (6,0), (...