Corridx is a preprocessor which stands between your LaTeX run and makeindex. It corrects index entries, in cases where the natural way to express an index item is bad for index sorting. So, for example, it can simply transform an entry \index{1,2-ethanediol} to \index{ethanediol@1,2-ethanediol}, which will be sorted as you might hope, rather than in amongst the numbers.

The program is distributed as Pascal source, though a win32 executable is also available; the documentation shows how to integrate it with winedt.

The program has now been superseded by a LaTeX package which does the job on the fly.