show a bitmap in MFC

[Angela2010]

Hi all,
I use a dialog in MFC to load and show a bmp successfully, I use a picture control , now I want to mark part of the bmp with red color with the following code:

     CWnd *pWnd=GetDlgItem(IDC_STATIC1); 
     CRect rect;
     pWnd->GetClientRect(&rect);
     CClientDC dcImage1(pWnd);
     COLORREF col=RGB(255,0,0);
          for( int i = 200; i < 300; i++)
	for(int j = 200; j < 300; j++)
	    dcImage1.SetPixel(i,j,col);
     pWnd->InvalidateRect(&rect);

the red part disappeared at once as the bmp was loaded, I just can not make the bmp and the red part I marked show at the same time, can anyone help me with this ,thank you very much,
the following is part of my code to load the bmp:

m_st1.GetClientRect( &rectStaticClient );  // define a variable of the picture control: CStatic m_st1
...
m_st1.ClientToScreen( &rectStaticClient );
ScreenToClient( &rectStaticClient);
...
GetObject( m_hBmpNew , sizeof(BITMAP), &m_bmInfo );
...
InvalidateRect(&rectStaticClient);