comboboxes, win32 and capi subclassing

Greetings, Lispers!

How can I subclass capi classes? For example, capi:option-pane class. How can I make my own my-option-pane class that is a descendant of capi:option-pane and its parents, implementing all those methods and slots in my class?

Why do I need it? Let's say that on Win32 capi:option-pane when using for simple selection (no editing) has a "non-canonical" look. See http://msdn.microsoft.com/en-us/library/bb775791(v=VS.85).aspx and look at "drop-down" and "drop-down list" combo boxes. To me capi:option-pane for simple items selection should look like "drop-down list". On XP there is almost no difference in the look of comboboxes, but on Win7 there is a difference.

In the attachment there is a code. The main function to run is (main). The first combo box is a standard capi:option-pane. The second one is created with win32 calls. And that brings me to my first question. How can I subclass capi:option-pane to hide all my win32 class "under the hood"?

Best,
 Art