Please back up a step: why do you want to delay what script?
All scripts are usually loaded at startup and later loading only works for a very limited number of scripts for the same reason that you need to start a new game after adding most scripts: they need the initialisation done at new game to function properly.
Now, if you want some function of the script delayed the way to go is to condition that function on the use of a switch and trigger that switch in your game.
That usually requires a rewrite of parts of the script, and it can't be done in general but is different for each script.
So please link us to the script you're talking about, and then we can check what is possible.