According to the online guide (http://www.choiceofgames.com/make-your-own-games/customizing-the-choicescript-stats-screen/) if you wanted to have Magic as a hidden stat, the code in the choicescript_stats file would be:
*if KnowsAboutMagic
*stat_chart
percent Magic
I then have the following line in the startup file:
*create KnowsAboutMagic false
I then have the following line in one of my later files, when I want the player to see the stat:
\*temp KnowsAboutMagic true
However, it still doesn’t appear in the stats screen.
Could someone please let me know what I’m doing wrong?
If I’m not wrong, *temp is used to create a new, temporary variable. Try using *set and tell us the results, if we’re lucky it will be just that 
@Aquila Thanks! I’ve just shut down my computer for the evening, but will give it a shot when I’m back online.
Does anyone else find coding strangely addictive? I’ve just started writing a game this evening, which probably wasn’t a smart move on a work night.
@Aquila
In startup you do this
*create knowsaboutmagic "false"
*create magic ""
and in the stats you would have
*if knowsaboutmagic = true
*stat_chart
percent magic
and then when you want it to display, you do this
*set knowsaboutmagic true
It works! Thank you both.