If you want to use a newer version of Directx, you need to be willing to sacrifice the multiplayer networking aspect of DarkGDK. It's based on DirectPlay, which was deprecated and was left out of the newer versions.
Open your DarkGDK directory and go into Lib->vs9 and rename Multiplayer.lib to Multiplayer_old.lib or something like that.
I attached a dummy Multiplayer.lib (one that has everything defined, but empty) because I couldn't find the thread about it.
Just put the attached lib into the folder, and you should be able to use August 2009.
PS: Your English is great.
"A computer once beat me at chess, but it was no match for me at kick boxing."
Emo Philips