There are a lot of things you can do with right click menus.
To set it up:
var myMenu:ContextMenu = new ContextMenu();
From there you can use a number of different methods like hiding the built in items or adding your own.
For example:
var myMenu:ContextMenu = new ContextMenu();
myMenu.hideBuiltInItems();
var myItem:ContextMenuItem = new ContextMenuItem();
myItem.caption = "Hello";
myItem.onSelect = function() {
trace("Hello");
};
myMenu.customItems = [myItem];
menu = myMenu;
There are countless possibilities. Experimenting is the best way to learn it.