Code:
var %a = $readini($mircdirsettings.ini,n,options,user1)
var %b = $gettok(%a,-1,124)
%a = $gettok(%a,1--1,124)
%a = $+(%a,$chr(124),$iif(%b = on,off,on)
.writeini -n $mircdirsettings.ini options user1 %a