This function moves to the previous character in a string.

#define INCL_WINCOUNTRY /* Or use INCL_WIN, INCL_PM, */
#include <os2.h>

HAB      hab;             /*  Anchor-block handle. */
ULONG    ulCodepage;      /*  Code page. */
ULONG    ulCountry;       /*  Reserved value, must be 0. */
PSZ      pszStart;        /*  Character string that contains pszCurrentChar. */
PSZ      pszCurrentChar;  /*  Current character. */
PSZ      pszPrevChar;     /*  Previous character. */

pszPrevChar = WinPrevChar(hab, ulCodepage,
                ulCountry, pszStart, pszCurrentChar);