Basically it's a macro that can change individual buttons into another button. For a simple example, you have cure in button 1, and the macro in button 2. You press the /hotbar set macro, and button 1 can change from cure into bio, depending how you wrote the macro. What this person wants is the ability to change the button into anything that can be slotted into hotbars/crossbars instead of just combat skills.

What everybody was wondering and arguing was why he even needs non combat skills be available to be slotted like this in the first place. He came up with confusing reasons that just made everybody question him some more. It turns out that he has a physical condition that requires him to play differently to play like other people.

Congrats by the way, ariaandkia. Looks like you're getting what you want. Not trying to be sarcastic here.