The check box on the attributes editor page uses javascript for that, I've looked into getting it working on the character sheets but there is no way without using jscript of creating that kind of checkbox. The closest thing I can think of is to use the @{selected|XXXmacro} assigned on the character sheet where XXX is the name of the macro, all you need do is mouse over memo fields and they'll give the macro name. With a bit of luck, r20 will eventually allow us some basic jscript commands for assigning to a token action and perhaps if we are extremely lucky basic conditional checking.