Are /copy to maytalble_back.dbf with cdx/ or /copy file ... to maytalble_back.dbf/ not enough?

>*.bak files are not useful enough because
>the only save the struct of a file, not the data
>
> How can I do so that at each uptdate of my data,
> a backup file of my dbt to be created
>
> eg.
> mytable.dbf to mirror a mirror file maytalble_back.dbf
>
> Thanks
>
> Moises