Trees, Lists and Check Boxes

[P-Cubed]

I'm looking for some assistance extending the TreeListCtrl class to
include the check box ability of the CustomTreeCtrl as well as 3-state
check boxes.

Main Column                          Column1
-----------------------------------------    -------------
[o] Child1
|-----[  ]Child1.1
|-----[  ]Child1.2
|-----[o]Child1.3
       |-----[  ]Child1.3.1                Value1
       |-----[  ]Child1.3.2                Value2
       |-----[  ]Child1.3.3                Value3
       |-----[X]Child1.3.4                Value4
[o] Child2
|-----[  ]Child2.1
|-----[  ]Child2.2
|-----[  ]Child2.3
|-----[o]Child2.4
       |-----[  ]Child2.4.1                Value1
       |-----[X]Child2.4.2                Value2
       |-----[  ]Child2.4.3                Value3
       |-----[  ]Child2.4.4                Value4
[o] Child3
|-----[  ]Child3.1
|-----[  ]Child3.2
|-----[  ]Child3.3
|-----[  ]Child3.4
       |-----[  ]Child3.4.1                Value1
       |-----[  ]Child3.4.2                Value2
       |-----[  ]Child3.4.3                Value3
       |-----[  ]Child3.4.4                Value4

Any ideas on the easiest and most effective way to do this?