I´m looking for a community on the web, that is working on the
creation of an Computer adventure. I would like to join such a group
to bring in my experience, but I havent found a place where I could
joined such a group. I´m just interested in the creation of such a
adventure game.

Hi there, joho!

Have I got just the place for you:

MyAdventureGame.com
http://www.myadventuregame.com

Founder and Lead Project Developer Alex Papadimoulis is a regular
customer hereabouts, challenging the Researchers to create new and
interesting Adventure Games.  The site is well put together,
entertaining, and has a very busy community.

You can create your own game by registering at the site, or for more
information, give Alex a shout at info@myadventuregame.com .

Have fun!

--Missy