Поиск подстроки в строке с русскими и английскими буквами. strstr() не справляется

#include <windows.h>
#include <stdio.h>
#include <conio.h>
#include <iostream.h>
struct string{char el[260];};
int counter = 0;
TCHAR head2[260]; 
HWND handlers[260];
string titles[260];
BOOL CALLBACK EnumChildProc(HWND hWnd,LPARAM lParam)
{
    TCHAR buff[260], head[260]; 
      //CharToOem(head2,head2);
   strcpy(head,head2);
// CharToOem(head,head);
    GetWindowText(hWnd, buff, 260);//CharToOem(buff, buff);
    if(strstr(buff,head)){
    handlers[counter]=hWnd;
    printf("%d HWND: %d   ",counter,hWnd);    
  //  CharToOem(buff, buff); // russian text support
    printf("title: %s\n", buff);
    counter++;
    if(lParam == 0) EnumChildWindows(hWnd, EnumChildProc, 1);
    return TRUE;}    // continue enumeration
}
int main(int argc, char* argv[])
{ //setlocale(LC_ALL, "Russian_Russia.1251");
    char ch;
int n;
lable1:
    cout<<"Enter title, or part of it\n";
   cin>>head2; 
   
   // cin<<
    printf("all exeptable windows...\n");
    EnumChildWindows(NULL, EnumChildProc, 0);
    printf("\nFound %d windows\n", counter);
     printf("Do u wanna new search? y/n\n");
    cin>>ch;if(ch=='y') goto lable1;else if(counter==0) return 0;
    cout<<"Enter number of window u wanna work to\n";
    cin>>n;
    cout<<"Hide it? y/n\n";
    cin>>ch;if(ch=='y')  ShowWindow(handlers[n], SW_HIDE); 
    cout<<"Show it? it? y/n\n";
     cin>>ch;if(ch=='y')  ShowWindow(handlers[n], SW_SHOW); 
     system("pause");
    return 0;
}