Handling DirectX 9 texture

[ElfQT]

Hi.

I would like some sample code which demonstrates how can I modify 
a DirectX 9 texture. (C++ or D, doesn't matter.) I have a 
texture, like a billboard, and I would like to draw on that.

I already looked on google, on different gamedev sites etc. 
haven't fount a working solution. I try the D forums (besides 
that my goal is to write my program in D), because a lot of great 
skulls used to be around here...

As a texture quad, here's a sample: 
http://www.drunkenhyena.com/cgi-bin/view_cpp_article.pl?chapter=2;article=30

If I try to modify the loaded texture, whatever I try 
(UpdateTexture, UpdateSurface, different D3DUSAGE, D3DPOOL, 
etc.), it crashes (with the much telling D3DERR_INVALIDCALL 
error).

I need explicitly DirectX 9 (not openGL), and possible without 
the usage if D3DX (like D3DX sprites).

Thanks,
  ElfQT