Kozak headed home to seal a 2-0 win for Aston Villa over Cardiff City at the weekend, and it marked his first home goal for the club.
"I feel fantastic because it's my first goal at Villa Park," said the Czech.
"It's an amazing atmosphere. I'm happy for the important victory and for my goal. It's beautiful. The fans helped us, they are good fans, incredible.
"We had other chances, myself and Christian Benteke. We played very well and we won. We pressed high, we wanted to win the game, It was important in the end."
Kozak, who is set to play for Czech Republic against Canada, is looking forward to the clash at the Hawthorns.
"It is another important game after the international break," Kozak said.
"We must concentrate on that game. West Bromwich will be a hard adversary, but if we play like we did against Cardiff I think we can win.
"It's my first derby and I'm excited for this game. For everybody it is important."