Have you tried running the old program on a more recent release of MATLAB?
MATLAB 6.0 (R12) is eighteen years old (released in November 2000) and I think it highly unlikely you'll be able to get it working on a new operating system. The Windows system requirements lists several Windows versions on which that release was supported, the newest of which was Windows ME which was released in September 2000. Microsoft ended mainstream support for this OS in 2003 and ended extended support in July 2006 according to Wikipedia.
