Прозрачный фон у Radio Button

#include <windows.h>
#include <stdio.h>
 
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
ATOM RegMyWindowClass(HINSTANCE, LPCTSTR);
HBITMAP hBitmap;
HINSTANCE hInstance;
 
int APIENTRY WinMain(HINSTANCE hInstance,
    HINSTANCE         hPrevInstance,
    LPSTR             lpCmdLine,
    int               nCmdShow)
{
    LPCTSTR lpzClass = TEXT("My Window Class!");
    if (!RegMyWindowClass(hInstance, lpzClass))
        return 1;
    HWND hWnd = CreateWindow(lpzClass, TEXT("Window"), WS_OVERLAPPEDWINDOW|WS_VISIBLE , 300, 300, 190, 200, NULL, NULL, hInstance, NULL);
 
    if(!hWnd) return 2; 
    MSG msg = {0};
    int iGetOk = 0;
    while ((iGetOk = GetMessage(&msg, NULL, 0, 0 )) != 0)
    {
        if (iGetOk == -1) return 3;
        TranslateMessage(&msg);    
        DispatchMessage(&msg);
    }
    return msg.wParam;
}
 
ATOM RegMyWindowClass(HINSTANCE hInst, LPCTSTR lpzClassName)
{
    WNDCLASS wcWindowClass = {0};
    wcWindowClass.lpfnWndProc = (WNDPROC)WndProc;
    wcWindowClass.style = CS_HREDRAW|CS_VREDRAW;
    wcWindowClass.hInstance = hInst;
    wcWindowClass.lpszClassName = lpzClassName;
    wcWindowClass.hCursor = LoadCursor(NULL, IDC_ARROW);
    wcWindowClass.hIcon = NULL;
    return RegisterClass(&wcWindowClass);
}
 
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    static HWND hRadioButton;
 
    switch (message)
    {
        case WM_CREATE:
        {
            hBitmap = (HBITMAP)LoadImage(hInstance, "myimage.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE | LR_CREATEDIBSECTION);
            hRadioButton = CreateWindowExA(0, "BUTTON", "radio button", (WS_CHILD | WS_VISIBLE | BS_RADIOBUTTON), 10, 10, 100, 20, hWnd, (HMENU)3001, hInstance, NULL);
            break;
        }
 
        case WM_PAINT:
        {
            BITMAP bm;
            PAINTSTRUCT ps;
            HDC hdc     = BeginPaint(hWnd, &ps);
            HDC hdcMem  = CreateCompatibleDC(hdc);
            SelectObject(hdcMem, hBitmap);
            GetObject(hBitmap, sizeof(bm), &bm);
            BitBlt(hdc, 0, 0, bm.bmWidth, bm.bmHeight, hdcMem, 0, 0, SRCCOPY);
            DeleteDC(hdcMem);
            EndPaint(hWnd,&ps);
        }
        break;
 
        case WM_DESTROY:
            PostQuitMessage(0);
        break;
 
        default:  
            return DefWindowProc(hWnd, message, wParam, lParam);
    }
    return 0;
}

    case WM_CTLCOLORSTATIC:
    {
        if((HWND)lParam == hRadio)
        {
            SetBkMode((HDC)wParam, TRANSPARENT);
            return (LRESULT)GetStockObject(NULL_BRUSH);
        }
        return 0;
    }

#pragma comment(linker, "/manifestdependency:"type='win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' processorArchitecture='x86' publicKeyToken='6595b64144ccf1df' language='*'"")

    case WM_CTLCOLORSTATIC:
    {
        if((HWND)lParam == hRadio)
        {
            RECT rc;
            GetClientRect((HWND)lParam,&rc);
            FillRect((HDC)wParam, &rc, hBlueBrush); 
            return (LRESULT)GetStockObject(NULL_BRUSH);
        }
        return 0;
    }