C / C++ / MFC

HMODULE hModule;
HRSRC hResource;

hModule = LoadLibrary(...);
if (NULL != hModule)
{
    hResource = FindResource(hModule, ...);
    if (NULL != hResource)
    {
        LoadResource(hResource, ...);
    }

    FreeLibrary(hModule);
}

CFileDialog dlg(FALSE);
CString fname = dlg.GetPathName(); 
const char* szBuffer = fname.GetBuffer(0);
int i = fname.GetLength();

CFile f;
// CFile::modeWrite is OK if you want to append
// data to the end of the file. If you're looking
// to create a new file and have it contain JUST this
// filename, you need to open the CFile with the 
// CFile::modeCreate flag.
if( f.Open ("F:\\test\\id.txt", CFile::modeWrite ) )
{
  try{
    f.Write(szBuffer, i);
    f.Close();
  } catch (CFileException *e)
  {
    AfxMessageBox ("Error!");
    e->Delete();
  }
}
// And remember to release your string pointer.
fname.ReleaseBuffer();

CFileDialog dlg(FALSE);
CString fname = dlg.GetPathName(); 
char* szBuffer = NULL;
int i = 0;

CFile f;
if( f.Open ("F:\\test\\id.txt", CFile::modeRead ) )
{
  try {
    // Get the size of the file.
    i = f.GetLength();
    // Create buffer to hold file data.
    szBuffer = new char[i];
    // Read in the file data
    if(szBuffer != NULL)
      f.Read(szBuffer, i);
    // Close the file.
    f.Close();
  } catch (CFileException *e)
  {
    AfxMessageBox ("Error!");
    e->Delete();
  } // end TRY-CATCH
} // end IF

// If szBuffer != NULL, it contains the file data.
// Do whatever you want to it, and then make sure you 
// clean up the dynamic memory you new'ed.
if(szBuffer != NULL)
  delete [] szBuffer;

CFileDialog dlg(FALSE);

dlg.DoModal();

CString fname = dlg.GetPathName();
const char* szBuffer = fname;
char s[128];

int i = lstrlen(szBuffer);

CFile f;
if (f.Open("F:\\test\\id.txt", CFile::modeWrite | CFile::modeCreate) == TRUE)
{
    try
    {
        f.Write(szBuffer, i);
    }
    catch (CFileException *e)
    {
        AfxMessageBox ("Error writing!");
        e->Delete();
    }

    f.Close();
}

if (f.Open("F:\\test\\id.txt", CFile::modeRead) == TRUE)
{
    try
    {
        f.Read(s, i);
    }
    catch (CFileException *e)
    {
        AfxMessageBox ("Error reading!");
        e->Delete();
    }
}