NinjaTrader 8 Custom Indicators

Hello! I need is a bar count indicator for NinjaTrader 8. Essentially you would click on a bar in a chart, drag it to another point to count the number of bars, then have those number of bars projected from the second point. For example, click on a low, drag it to a high and see how many bars that is, for example 59 bars, then have 59 bars projected from the high (second point).
I’ve recorded a short loom video to show you what I’m looking for:
https://www.loom.com/share/b22941d3c30242ffbe8a484bf23db532