This spreadsheet study produces an oscillator of the relationship of price to the previous zigzag swing high/low.
Click on each of these links to download:
ZigZag Price Osc-.StdyCollct
ZigZag Price Osc.scss
and put both files in your Sierra Chart \Data folder, then click on Analysis >> ZigZag Price Osc-
The formulas use the Last price as the reference. If you want it based on something else, edit the formulas in cells K3 and L3, replacing E4 with your preferred row 4 reference or formula.