SubClassing BUTTON class

I want to subclass the system Button class (not MFC), so far I just changed the callback of all the button windows in a dialog to a new callback of my own, which handels WM_PAINT, and then callls the controls orignal WNDPROC function.
Understood.

I can get the class WndClass structure of the systems Button class and and get its default WNDPROC function,
You are now talking about what is called global subclassing.
but I don't know if I can reregister it so I won't have to use the method which I'm using now. It will be better that way since I won't have to get each control WNDPROC and store it...
This is not clear. Can you elaborate on this ?
In general my current problam is to get the control state, and by state I mean each of the button appearance which I think are: Normal, Pressed, Highlighted, focused and disabled (XP style ....)

So far I monitored the state of the control because the control doesnt notify when it redraws itself after changing state,
I monitored its state using WM_MOUSEMOVE, WM_LBUTTONDOWN and alll related messages but that just like making a new control and not subclassing one...
Fair enough. But, that is the way to do what you want to achieve. You may be right that, a button class is not even required. But think about other things like tabbing through controls, having hot keys for the controls, using space bar to place focus on a button and such. These come with the BUTTON class. So, if you need this, subclassing is still the way to go, else , you are better off writing your own class.