how do you get Artillery support in the mission editor for SP and MP missions?

Do you mean like this or just calling in artillery hardcore scripted? The harcore scripted version take less time before the artillery hits the location but the other one have one problem. You get random mission that suck. You can cancel them but they can be a pain in the ass. The hardcore scripting you can find in Mr Murrays Editor "book" which you can find here.
the other one you can find here: How to make the 2nd
Here how it look if you take the 2nd one: My Youtube Vid

EDIT: Oh sorry didnt see you were a Armed Assault player. Then you can only take the first one from Mr Murrays Guide.

i cant download the editor book for some reason