The <@> command is used to invoke sequences of EFI$CP commands.

    Procedures can be nested up to four levels deep.

    Note that specifying the @ command on the EFI$CP command line
    will not accomplish the same thing as from the EFI$CP prompt.
    When an @ is used from the DCL command, DCL processes the @ and
    only the first line of the data file will be passed as input to
    EFI$CP and the rest will be treated as DCL commands.

    EFI$CP> @COPY_FILES.EFI$COM