Directx9 index buffers and multiple threads

Im trying to write a 3DS loader that has an OpenGL rendering implementation for use in my general rendering system.

The problem here is that I have vertices indexed to one array and texture coordinates indexed to another. I don’t want to generate a new set of indices and source vertices by checking each combination of vertex coordinates and texture coordinates, so how can I define two arrays in directx buffers optimally?

I would like to have 3 vertex buffers, one for vertices, one for texture coordinates and one for vertex normals. Then I would have index buffers for all three. I do not know how to do that.

I work in directx9 and c ++