Wow! Thanks a lot!
I have modified a bit and now I have advanced footsteps on request.
I choose the group, the intervals between steps (whether the player is walking or running) and how long the steps should last. And the system randomizes the sound and performs a light retouching with the filter.
This is amazing, cool, wonderful, brilliant, gorgeus, spectacular, beautiful, stunning!
damn, I didn't know that I know so many cool words in English! :-D