SOUTH KOREAN WON FIXED AT 25-MONTH HIGH THE BANK OF KOREA SAID IT FIXED THE MIDRATE OF THE WON AT 844.30 TO THE DOLLAR, ITS HIGHEST LEVEL SINCE FEBRUARY 26, 1985, WHEN IT WAS 843.90. THE WON WAS SET at 845.50 YESTERDAY. THE WON HAS RISEN 2.03 PCT AGAINST THE DOLLAR SO FAR THIS YEAR, AFTER RISING 3.34 PCT IN 1986.