As described in Larry Williams' book "Long Term Secrets of Short Term Trading".
I've rethought, corrected, and rewritten this code, replacing the original post.

Though the code is simple, this indicator is worthy of your study for the way it performs in the market.
On a chart, the ShowMe will indicate where one would have entered long or short on the day after a SmashDay. Examine the placement of the trades to get a visual feel of whether you like this strategy or not.

In my article in this issue, "Trading Stochastic Pops," I present a technique for identifying breakouts in stock prices using stochastic pops, whichrefers to a pop, or breakout, in price that leads to a high reading onthe stochastics oscillator.
My stochastic pop technique was introduced to the Market Technicians Association in autumn 1999. One of my MTA colleagues promptly dubbed itthe "PopSteckle." Matt Samojeden, president of the St. Louis Omega UsersGroup, was of invaluable assistance in writing this TradeStation code forthe technique.

Shows the bar that is N bars back.
Useful to see what bar is being compared for momentum, highest, etc. Also useful to see what bar is about to be compared. Since you only want one moving "Show Me", using a trend line is appropriate here, since traditional Show Me's persist. The trend line is degenerate in that the start and end point is the same. The idea is to make the "line" thick so it shows up as a square dot in the center of the appropriate bar.