Zooming In on a Selection: Step 7
LeadBitmap.SetDstRect(&rLeadDest);
LeadBitmap.SetClipDstRect(&rLeadDest);
LeadBitmap.SetSrcRect(&rLeadSource);
LeadBitmap.SetClipSrcRect(&rLeadSource);
HDC hDC;
hDC = ::GetDC(this->m_hWnd);
LeadBitmap.Paint()->SetDC(hDC);
LeadBitmap.Paint()->PaintDC();
::ReleaseDC(this->m_hWnd, hDC);