ComboDropDown - GridInGrid

Hi,

I am trying to create a ComboDropDown, where the popup contains a Grid and two Buttons. Some Controls in the Grid also contains a Grid as DropDown Control. My problem is, that the PopUp Control of the ComboDropDown closes, when the next Grid DropDown is opened.
This is what I have done:
- I created a control with a DataBoundGrid and two Buttons, which I called DropDownGrid. This grid works in a single Grid as a DropDown Control, to change the Value of a cell.
- I derived from ComboDropDown and overrides the CreatePopupContainer() Method to return a GridDropDownContainer.
- I also set the DropDownContainerParent with the GridDropDownContainer from the derived ComboDropDown.

Is it possible to create a control, where i can have theoretical up to unlimited DropDownGrids in the cell controls of DropDownGrids, starts from the ComboDropDown?

I know that the Grid DropDown Control also have a GridDropDownContainer, but doesn't know how to connect the GridCell GridDropDownContainer with the ComboDropDown GridDropDownContainer. So both or more popups are left open.

Hopefully someone can help me.

Regards
Christian