REREAD FILE=handle COLUMN=column.
The REREAD transformation allows the previous input line in a data file already processed by DATA LIST or another input command to be re-read for further processing.
The FILE subcommand, which is optional, is used to specify the file to have its line re-read. The file must be specified in the form of a file handle (see FILE HANDLE). If FILE is not specified then the last file specified on DATA LIST will be assumed (last file specified lexically, not in terms of flow-of-control).
By default, the line re-read is re-read in its entirety. With the COLUMN subcommand, a prefix of the line can be exempted from re-reading. Specify an expression (see Expressions) evaluating to the first column that should be included in the re-read line. Columns are numbered from 1 at the left margin.
Issuing REREAD multiple times will not back up in the data
file. Instead, it will re-read the same line multiple times.