How to ignore (undo) the WM_SETFOCUS for the new window and WM_KILLFOCUS for the old one, keeping the rest of the processing?

Question

Lets say I have a frame window containing an EDIT and a BUTTON controls, I need to keep the focus always on that edit control whenever I click on the button, and continue the normal button click processing altering the edit content (a behavious very similar to the Spin Control buttons). is there anyway to to achieve this (like to intercept the focus change and prevent it from happening at all or at least undo it) ?

TIA.

I have tried WM_MOUSEACTIVATE returning MA_NOACTIVATE but it didn't work for me, I guest this is because the main frame I work on is already active when I click the button.