Yes, it's a private add-on of mine, I can add gadgets for it, so yeah.
I get a error on console saying 
"DarrenGUI unknown command"
with this bit of editation, see where I have gone wrong? 
Tell me!
exec("Add-Ons\Script_DarrenMods.zip\gui.gui");    // TAKE THIS OFF IF YOU DON'T NEED
if(!$DarrenGUI)
{
   $remapDivision[$remapCount] = "DarrenMods";
   $remapName[$remapCount] = "GUI";
   $remapCmd[$remapCount] = "DarrenGUI";
   $remapCount++;
   $DarrenGUI = true;
}
function DarrenGUI(%val)
{
    if(!%val) 
    {
       return;
    }
   canvas.pushDialog(Add-Ons\Script_DarrenMods.zip\gui.gui);
}