Spawning at a particular point

I know how to spawn an option but I can't work out how to get it to spawn at a particular position on the screen.

System.Spawn Object

As an action to any given event:

System: Create object

Inside that there will be x and y coordinates. You can use expressions (such as "get x of ____" and calculations such as "displaywidth/2").

One of my debug tricks is to spawn an object at a random screen position by using

Create object at

x = "random(displaywidth)"

y = "random(displayheight)"

Aaah ... I was use the spawn option under the individual sprite and not the system creation ... thanks