D3DXSaveSurfaceToFile - Random file name?

Question

i'm trying to save multiple .bmp files with the D3DXSaveSurfaceToFile method but unable to solve it, i've tried making random strings/wstrings & convert them to LPCWSTR/LPCSTR, using D3DXSaveSurfaceToFileW / D3DXSaveSurfaceToFileA, but all i get is gibberish.

Any ideas of how to do it? (My project is in C++, Visual Studio, DirectX June 2010)

Answer 1

My solution, if anyone wants it (used char instead):

        static int fileIndex = 0;
        char fileName[20] = "capture";
        sprintf_s(fileName, sizeof(fileName), "%s%d.jpg", fileName, fileIndex);
        //sprintf(fileName, "%s%d.jpg", fileName, fileIndex);

        size_t size = strlen(fileName) + 1;
        wchar_t* wFileName = new wchar_t[size];

        size_t outSize;
        mbstowcs_s(&outSize, wFileName, size, fileName, size - 1);
        //mbstowcs( wFileName, fileName, size - 1);
        LPWSTR ptr = wFileName;

        D3DXSaveSurfaceToFile(ptr, D3DXIFF_JPG, p, nullptr, nullptr);

        fileIndex++;