filespec

    Specifies the image file to be patched or a command procedure
    that contains both the name of the image file to be patched and
    PATCH commands.

    If the file specification denotes an image file, the file
    specification must contain the file name. If you omit the
    remaining fields (device, directory, file type, and version
    number), PATCH uses your default device and directory, assumes
    a file type of EXE, and uses the highest version of the image
    file.

    If the file specification denotes a command procedure, the
    filespec parameter must be preceded by an at sign (@). Only
    the file name is required. If you omit the remaining fields
    (device, directory, file type, and version number), PATCH uses
    your default device and directory, assumes a file type of COM,
    and locates the highest version of the command procedure.

    The asterisk (*) and the percent sign (%) wildcard characters are
    not allowed in the file specification.