Can we not use ternary expression in menu item header

[JTRTech]

Am trying to work out best solution for our daily specials.
Dont want open access to backend and navigate module cant be narrowed down to a specific product or order tag so am back to my custom entity screen using program settings and adding a automatic freetag order tag and updating price.

This is my entity screen so far;

Which updates global program settings;

However the amount of specials changes so was hoping to use a ternary expression in the menu item header;

However it doesnt seem to work - that or ive got the expression wrong;

So as to avoid the just £ like on what would be specialstarter4

Also tried using a custom menu item button but same result.

[JTRTech]

Solved, used script in the end - on a custom button but thats irreverent to the question;