A special form of the STORE statement inserts a segment into a
    segmented string. Storing a segmented string requires four steps:

    1. Create a segmented string with the CREATE_SEGMENTED_STRING
       statement. See HELP on CREATE_SEGMENT.

    2. Store each segment using the syntax shown in the following
       Format section. You must use the special Oracle Rdb value
       expression RDB$VALUE or RDB$LENGTH as the segment name in
       the USING clause.

    3. Store the entire segmented string using the usual syntax for
       storing records in relations. Use the segmented string handle,
       declared in the CREATE_SEGMENTED_STRING statement, as the
       value expression in this USING clause.

    4. Close the segmented string.