C / C++ / MFC

how to send at commands over serially via comport using C compiler and what will be the code

Graphics graphics(pDC->GetSafeHdc());
	Image myPNG(path);
	if(myPNG.GetLastStatus()!=Ok)
	{
		return FALSE;
	}

	graphics.DrawImage(&myPNG, (INT)image_rect.left, (INT)image_rect.top, 300, 300);
	return TRUE;

// Variables declaration in header file	
LONG		Width;
LONG		Height;
LONG		bpp;
LONG		Stride;
BITMAPINFO*	bmi;
BYTE*		pDIBSectionBits;
HBITMAP		hbm;
Graphics*	imagedisp;
Bitmap*		offscreenBitmap;
CWnd* Display;
CStatic m_ImageDisp;

// Source file
OnInitDialog()
{
......
  Width = 512;
  Height = 512;
  bpp = 8;	
  Stride = ((Width * bpp + 31L) & (~31L)) / 8L;
......
}

InitParams()
{
  SetImageColor();	

  Display = GetDlgItem(IDH_IMAGE);
  this->GetClientRect(&m_disp_rect);	
  Display->GetClientRect(&m_disp_rect);
  m_ImageDisp.GetClientRect(&m_disp_rect);
  imagedisp = new Graphics(m_ImageDisp.GetDC()->GetSafeHdc());
}

SetImageColor()
{
  m_BUpdate = false;
  if (bmi != NULL)
  {
	delete bmi;
	bmi = NULL;
  }
  bmi = (BITMAPINFO *)new BYTE[sizeof(BITMAPINFO) + UCHAR_MAX * sizeof(RGBQUAD)];
  bmi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
  bmi->bmiHeader.biWidth = Width;
  bmi->bmiHeader.biHeight = Height;
  bmi->bmiHeader.biPlanes = 1;
  bmi->bmiHeader.biBitCount = (WORD)bpp;
  bmi->bmiHeader.biCompression = BI_RGB;
  bmi->bmiHeader.biSizeImage = 0;//Stride * abs(Height);
  bmi->bmiHeader.biXPelsPerMeter = 0;
  bmi->bmiHeader.biYPelsPerMeter = 0;
  bmi->bmiHeader.biClrUsed = 0;
  bmi->bmiHeader.biClrImportant = 0;
  memcpy(bmi->bmiColors, USECOLORMAP?summercmap:greyscale, 256*sizeof(RGBQUAD));
  hbm = ::CreateDIBSection(NULL, bmi, DIB_RGB_COLORS, (void**)&pDIBSectionBits, NULL, 0);	
  if (offscreenBitmap != NULL)
  {
	delete offscreenBitmap;
	offscreenBitmap = NULL;
  }
  offscreenBitmap = new Bitmap(bmi, pDIBSectionBits);
  m_BUpdate = true;
}

OnPaint()
{
  CPaintDC dc(this); // device context for painting
  // TODO: Add your message handler code here
  if (m_BUpdate)
  {
	BYTE *pCurRowPixel = (BYTE *)(pDIBSectionBits);
		memcpy(pCurRowPixel, ImgBuff, Width*Height);
	
	imagedisp->DrawImage(offscreenBitmap, 0, 0, Width, Height);
  }
}