how to shade the area between 2 lines of a CategoryPlot?

[alsw-2000]

Hi guys,

I have generated a chart as follow:


However my user want to shade the area between the "Inner Cone (Lower)" and "Inner Cone (Upper)" series, and the legend also need to merge to "Inner Cone" like the following one.
Is there any function can do this?



Cheers,
alsw