directx9 meshes

Salut a tous.
Voila le tuto du sdk :
cela affiche un tigre avec texture,mais comment faire pour choisir la position dans un espace 3d?
Merci.

HRESULT InitGeometry()
{
    LPD3DXBUFFER pD3DXMtrlBuffer;

    // Load the mesh from the specified file
    if( FAILED( D3DXLoadMeshFromX( "Tiger.x", D3DXMESH_SYSTEMMEM,
                                   g_pd3dDevice, NULL,
                                   &pD3DXMtrlBuffer, NULL, &g_dwNumMaterials,
                                   &g_pMesh ) ) )
    {
        // If model is not in current folder, try parent folder
        if( FAILED( D3DXLoadMeshFromX( "..\\Tiger.x", D3DXMESH_SYSTEMMEM,
                                    g_pd3dDevice, NULL,
                                    &pD3DXMtrlBuffer, NULL, &g_dwNumMaterials,
                                    &g_pMesh ) ) )
        {
            MessageBox(NULL, "Could not find tiger.x", "Meshes.exe", MB_OK);
            return E_FAIL;
        }
    }

    // We need to extract the material properties and texture names from the
    // pD3DXMtrlBuffer
    D3DXMATERIAL* d3dxMaterials = (D3DXMATERIAL*)pD3DXMtrlBuffer->GetBufferPointer();
    g_pMeshMaterials = new D3DMATERIAL9[g_dwNumMaterials];
    g_pMeshTextures  = new LPDIRECT3DTEXTURE9[g_dwNumMaterials];

    for( DWORD i=0; i<g_dwNumMaterials; i++ )
    {
        // Copy the material
        g_pMeshMaterials[i] = d3dxMaterials[i].MatD3D;

        // Set the ambient color for the material (D3DX does not do this)
        g_pMeshMaterials[i].Ambient = g_pMeshMaterials[i].Diffuse;

        g_pMeshTextures[i] = NULL;
        if( d3dxMaterials[i].pTextureFilename != NULL &&
            lstrlen(d3dxMaterials[i].pTextureFilename) > 0 )
        {
            // Create the texture
            if( FAILED( D3DXCreateTextureFromFile( g_pd3dDevice,
                                                d3dxMaterials[i].pTextureFilename,
                                                &g_pMeshTextures[i] ) ) )
            {
                // If texture is not in current folder, try parent folder
                const TCHAR* strPrefix = TEXT("..\\");
                const int lenPrefix = lstrlen( strPrefix );
                TCHAR strTexture[MAX_PATH];
                lstrcpyn( strTexture, strPrefix, MAX_PATH );
                lstrcpyn( strTexture + lenPrefix, d3dxMaterials[i].pTextureFilename, MAX_PATH - lenPrefix );
                // If texture is not in current folder, try parent folder
                if( FAILED( D3DXCreateTextureFromFile( g_pd3dDevice,
                                                    strTexture,
                                                    &g_pMeshTextures[i] ) ) )
                {
                    MessageBox(NULL, "Could not find texture map", "Meshes.exe", MB_OK);
                }
            }
        }
    }

    // Done with the material buffer
    pD3DXMtrlBuffer->Release();

    return S_OK;
}