program-name

    OpenVMS usage:char_string
    type:         character string
    access:       read only
    mechanism:    by descriptor

    File name of the program to be run in place of the current
    program. The program-name argument contains the address of a
    descriptor pointing to this file name string.

    The maximum length of the file name is 255 characters. The
    default file type is .EXE.