How to resize the column width in a splitterwindow

Hi,
I have some problems with my splitterwindow (static, 3 columns, 1 Row):

BOOL CMainFrame::OnCreateClient(LPCREATESTRUCT /*lpcs*/,
CCreateContext* pContext)
{
// create splitter window
if (!m_wndSplitterR.CreateStatic(this, 1, 2))
return FALSE;

if(!m_wndSplitterLM.CreateStatic(&m_wndSplitterR, 1, 2, WS_CHILD | WS_VISIBLE, m_wndSplitterR.IdFromRowCol (0, 0)))
return FALSE;

if (!m_wndSplitterLM.CreateView(0, 0, RUNTIME_CLASS(ViewLinks), CSize(1, 1), pContext) ||
!m_wndSplitterLM.CreateView(0, 1, RUNTIME_CLASS(ViewMitte), CSize(1, 1), pContext))
{
m_wndSplitterLM.DestroyWindow();
return FALSE;
}
if(!m_wndSplitterR.CreateView(0, 1, RUNTIME_CLASS(ViewRechts), CSize(1, 1), pContext) )
{
m_wndSplitterR.DestroyWindow();
return FALSE;
}

WINDOWPLACEMENT wind;
wind.flags=SW_SHOWMAXIMIZED;

m_wndSplitterR.SetColumnInfo (0, 350, 100);
m_wndSplitterLM.SetColumnInfo (0, 140, 100);
//GetCtivePane();
return TRUE;
}

The problem. I want to resize the middle pane but how? If I change the values of m_wndSplitterR or m_wndSplitterLM (SetColumnInfo(...)) I only can change the left and right column.