The SCRIPT() function allows you to refer back to a previously saved script without having to duplicate the original.
When you click on the SCRIPT() text in the script editor a window will display the Script Properties where you can select the script to use.
The following example is referencing the default Moving Average Crossover script with the additional criteria where the close is greater than the open.
SCRIPT(SCRIPTNAME=MA Crossover - MA1 Above MA2) and CLOSE() > OPEN()
This is demonstrated in the below chart using the Show Bar tool:
Where the existing script has multiple outputs - such as the Price Percentage Oscillator created here - then you can select which plot to be used in the new script. This example will return a result when the histogram (Plot 3) in the PPO turns down from a peak:
SCRIPT(SCRIPTNAME=PPO, PLOTNAME=Plot3) TurnsDown