Well, for healing, I wouldn't suggest using target swapping. It's cleaner and more reliable to use macro conditionals.

I'd start with the newbie's guides, of course. From there, understanding macros. And Fitzcarn's Macro Explain to see what a macro is trying to do.

If you really have to use this setup for healing, there's a lot of old threads about it -

http://www.dual-boxing.com/threads/5...eedback-wanted
http://www.dual-boxing.com/threads/8...arm-heal-focus
http://www.dual-boxing.com/threads/8...-Healing-Macro

Just search for focustargettarget.

But if you're using ATG, then you're using ISBoxer, which means you have access to VideoFX,
Repeater Regions and Click bars.

These are far more efficient than just blind auto-healing that you'd get with a static macro.