"COPY" is quite a complex command, for the sake of simplicity we will show you the basics.
"COPY WIN.INI C:\" will copy the win.ini file when you are in the correct directory to the C: drive
"COPY C:\WINDOWS\WIN.INI C:\" will copy the win.ini file when you are not in the correct directory to the C: drive
The file name and location can be obviously changed.
"COPY /?" will give you further help when using the command.