Disable default accelerators in Win32 for push buttons

I have a Win32 program that has push buttons in a window and a custom control object. When a right arrow key or left arrow key is pressed, a WM_KEYDOWN message is sent. It then gets translated to a WM_COMMAND since it is a default accelerator (left and right arrow keys). How can I disable this behavior and forward the WM_KEYDOWN message to my custom control?