treeview 3-state and 2-state checkboxes on different nodes - c++

Question

I have to create a treeview control in a class that inherits from CTreeCtrl. After many tries, I have created 3-state checkboxes for every node. And here comes my question - I need some child nodes to have only 2 states (checked or unchecked). Any clue on how can I reach that goal? I tried to add an if statement to change the behavior like this:
else if (itemState == INDEXTOSTATEIMAGEMASK(3))
{
SetItemState(hItem, INDEXTOSTATEIMAGEMASK(1), TVIS_STATEIMAGEMASK);
And it’s working! Except when an element is "selected", then it’s like ignoring every behavior I did in the OnLButtonClick event.
Is there some other event I don’t know about? Is there an easier way to get a 2-state checkbox only on some nodes and not others?
This is all i use to control the tree
void CSelDepTreeCtrl::OnLButtonDown(UINT nFlags, CPoint point)
{
CTreeCtrl::OnLButtonDown(nFlags, point);
UINT Flags = 0;
HTREEITEM hItem = HitTest(point, &Flags);
if ((NULL != hItem) && (TVHT_ONITEMSTATEICON & Flags))
{
auto itemText = GetItemText(hItem);
if (itemText.Left(1) == "C") {
if ((nFlags & (MK_SHIFT | MK_CONTROL)) || NULL == GetParentItem(hItem)) {
SetCheckChild(hItem, GetCheck(hItem));
}
}
if (itemText.Left(1) == "L") {
if ((nFlags & (MK_SHIFT | MK_CONTROL)) || NULL == GetParentItem(hItem)) {
SetCheckChild(hItem, GetCheck(hItem));
}
}
if (itemText.Left(1) == "S") {
auto itemState = GetItemState(hItem, TVIS_STATEIMAGEMASK);
if (itemState == INDEXTOSTATEIMAGEMASK(1))
{
SetItemState(hItem, INDEXTOSTATEIMAGEMASK(2), TVIS_STATEIMAGEMASK);
}
else if (itemState == INDEXTOSTATEIMAGEMASK(2))
{
SetItemState(hItem, INDEXTOSTATEIMAGEMASK(1), TVIS_STATEIMAGEMASK);
}
else if (itemState == INDEXTOSTATEIMAGEMASK(3))
{
SetItemState(hItem, INDEXTOSTATEIMAGEMASK(1), TVIS_STATEIMAGEMASK);
}
}
}
}