I am developing window application in that I am having 2 child windows on left and right side. I want to handle input events for both windows separately. How to achieve it?

My code: class EditorWindow : public DxWindow { public: CSplitterWindow m_vSplit; CPaneContainer m_lPane; CPaneContainer m_rPane; PropertyDialog m_propertyWnd; DECLARE_WND_CLASS(_T("Specific_Class_Name"))

    BEGIN_MSG_MAP(EditorWindow)
        MESSAGE_HANDLER(WM_CREATE, OnCreate)
        MESSAGE_HANDLER(WM_DESTROY, OnDestroy)
        MESSAGE_HANDLER(WM_LBUTTONDOWN, KeyHandler)
        MESSAGE_HANDLER(WM_KEYUP, KeyHandler)
        MESSAGE_HANDLER(WM_LBUTTONDOWN, KeyHandler)
    END_MSG_MAP()

    LRESULT OnCreate(UINT, WPARAM, LPARAM, BOOL&)
    {
        CRect rcVert;
        GetClientRect(&rcVert);     
        m_vSplit.Create(m_hWnd, rcVert, NULL, WS_CHILD | WS_VISIBLE | WS_CLIPSIBLINGS | WS_CLIPCHILDREN);
        m_vSplit.SetSplitterPos(rcVert.Width()/1.4f); // from left
        m_lPane.Create(m_vSplit.m_hWnd);        
        m_vSplit.SetSplitterPane(0, m_lPane);   
        //m_lPane.SetTitle(L"Left Pane");

        m_rPane.Create(m_vSplit.m_hWnd);    
        m_vSplit.SetSplitterPane(1, m_rPane);       
        m_rPane.SetTitle(L"Properties");
        m_propertyWnd.Create(m_rPane.m_hWnd);
        //m_vSplit.SetSplitterPane(SPLIT_PANE_LEFT, md.m_hWnd);

        return 0;
    }
    LRESULT OnDestroy( UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL &bHandled )
    {
        PostQuitMessage(0);
        bHandled = FALSE;
        return 0;
    }
    LRESULT KeyHandler( UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL &bHandled )
    {
        return 0;
    }

};