Moves the read/write pointer according to the type of move specified.

#define INCL_DOSFILEMGR
#include <os2.h>

HFILE     hFile;     /*  The handle returned by a previous DosOpen function. */
LONG      ib;        /*  The signed distance (offset) to move, in bytes. */
ULONG     method;    /*  The method of moving. */
PULONG    ibActual;  /*  Address of the new pointer location. */
APIRET    ulrc;      /*  Return Code. */

ulrc = DosSetFilePtr(hFile, ib, method, ibActual);