Partial Plot fill to show ROI

[Tim_C.]

Hello

I am trying to highlight a ROI onan XY chart

Example:1

SIGNALS

AC Sinewave, amplitude of 2

DC, Offset 0.5

DC, Offset -0.5

I would like to shade the areas from 0.5 to the peak of the sinewave

Example 2

Basically the same as example 1 except the DC with the offset of 0.5 could be an irregular plotted signal that could be sloped under the Sinewave peak or could be zig zagged a bit

I have tried different variations of plot fill or fill base but they fill the entire sinwave, I want toonly fill the top portion above the referance signal

Any help on this would be appreciated

Thanks in advacne

Tim c.