How to override variables for a specific host in director

I asked this in another post, but it was unrelated to the original question
, so I decided to make a new post. Here is the link to the original question: How to i pass positional paramaters

Here is the image in question, showing the overides, but having no effect on the alerts. is it posible to overide the variables in an alert on a single host? Thank you for your time!