Just a minute.
Let's make it simple. Just pretend we have three tools:
Center
Drill
Tap
You set the Center under the name "555" for instance. Drill "601" and Tap "790" in the magazine
You call the tool "555" and here machine puts the Center in the turret.
You call the tool "601" and here machine puts the Drill in the turret..
You call the tool "790" and here machine puts the Tap in the turret..
Isn't it?
Just for curiosity what it the "CNC" you have? is it lathe with magazine or combined machinetool?