CFile MyFile,WriteFile;
CFileException e;
char chFind;
char chRead[128];
MyFile.Open("C:\\XXX.txt",CFile::modeRead,&e);
int i=0;
while(i<MyFile.GetLength())
{
    MyFile.Read(&chFind,sizeof(chFind));
    if(ch == 's')
        break;
    i++;
}
MyFile.Seek(i,CFile::Begin);
MyFile.Read(&chRead,sizeof(chRead));
MyFile.Close();
WriteFile.Open("d:\\zzz.txt",CFile::modeWrite,&e);
WriteFile.Write(&chRead,sizeof(chRead));
WriteFile.Close;