Code boxes are simply text boxes that have been formatted for writing Mathematica code and given a special name. They are, in every other way, ordinary text boxes.
There are two ways of selecting a text box, selecting the box itself or selecting text inside the box. The selection border of the text box will be different in each case. To do anything other than edit the text inside the box you will need to make sure the box itself is selected. Once the box itself is selected, you can, for example, move it or resize it, copy and paste it to another location, or delete it.
When typing in a text box, be aware that Excel goes into a different mode. Most toolbar buttons, for example, are no longer available.
Excel while in edit mode.
As with many toolbar buttons, Mathematica macros do not work while Excel is in this mode. To get out of this edit mode, press the Esc key or click out of the box.
