GuiControl.add("My Text", ROW_ID);
This will add it to the bottom of the list.
GuiControl.addFront("My Text", ROW_ID);
This will add it to the top of the list.
ROW_ID does NOT represent the it's order in the list(unless you choose to do it that way) and is used in the functions GuiControl.getTextByID(ROW_ID); and GuiControl.setSelected(ROW_ID);