calling managed code from unmanaged in codeblocks

#include "main.h"
#include <windows.h>
#include <mscoree.h>
#pragma comment(lib,"mscoree.lib")
void DLL_EXPORT SomeFunction()
{
        ICLRRuntimeHost *pClrHost = NULL;
        HRESULT hr = CorBindToRuntimeEx(
        NULL, L"wks", 0, CLSID_CLRRuntimeHost,
        IID_ICLRRuntimeHost, (PVOID*)&pClrHost);
        hr = pClrHost->Start();
        DWORD dwRet = 0;
        hr = pClrHost->ExecuteInDefaultAppDomain(
             L"message.dll",
             L"message.Class1", L"message", L"Hello", &dwRet);
}

extern "C" DLL_EXPORT BOOL APIENTRY DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
{
    switch (fdwReason)
    {
        case DLL_PROCESS_ATTACH:
            // attach to process
            // return FALSE to fail DLL load
            break;

        case DLL_PROCESS_DETACH:
            // detach from process
            break;

        case DLL_THREAD_ATTACH:
            // attach to thread
            break;

        case DLL_THREAD_DETACH:
            // detach from thread
            break;
    }
    return TRUE; // succesful
}

Public Class Class1
    Function message(ByVal a As String)
        MsgBox(a)
    End Function
End Class