How to create a Custom DataGridViewCheckBoxColumn in Windows Forms C# 2008 ?

I want to create a custom DataGridViewCheckBoxColumn. First I created a custom CheckBox, and it works fine.
The checkbox has two appearances based on public boolean value "Adjustable" that I created. If Adjustable = false (default) the onpaint event won't be overridden, if it is true the onpaint event creates the custom appearance.
 
I now want to create a CheckBoxColumn in my DataGridView based on this checkbox.
I tried to create the type DataGridViewCheckBoxColumnCustom, this works fine, but I can't find how to set it to use my custom Checkbox.
 
I tried to create a celltemplate based on DataGridViewCheckBoxCell but I can't set my custom checkbox, and neither can I find an onpaint event.
 
So how do I create a custom DataGridViewCheckBoxColumn ?
 
Rob