/sys$common/syshlp/helplib.hlb Lexicals, F$ELEMENT, Arguments  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 element-number

    Specifies the number of the element to extract (numbering begins
    with zero). Specify the element-number argument as an integer
    expression. If the element-number argument exceeds the number of
    elements in the string, F$ELEMENT returns the delimiter.

 delimiter

    Specifies a character used to separate the elements in the
    string. Specify the delimiter as a character string expression.

 string

    Specifies a string containing a delimited list of elements.
    Specify the string as a character string expression.