Watch Toolbars 1 (video tutorial).
Drag the CLI button out of the Customize/Commands window on to your toolbar, then click it.
Alternatively, if you have the find-as-you-type field enabled in Opus, just type >CLI while in a directory. (Avoid special directories like Desktop and My Computer where FAYT doesn't work.)
You can force overwrites (i.e. of read-only files) and skip errors without prompting by passing the Copy command certain arguments. See the manual, under Opus Raw Commands, for descriptions of all the arguments.