UPDATE: Read this post and then download the version a few posts below. It will export the textures as seperate bmps which is nicer.
Although i posted this earlier already I thought I'd repost because it was difficult to find. This plugin will allow you to extract the geometry WITH inline textures.
Be sure to create the folder C:\VRML before. Then go to video settings in-game and activate the option. It is suggested to do this while the game is running, because otherwise you would have to wait a long time (dumping is slow).
The old vrml files i exported had a little syntax error thats why they didn't import in Cinema 4D. The new ones will do just fine. Unfortunately Cinema4D handles transparency differently than vrml so it is difficult to put that data in the vrml file as well....it might be possible to come up with a solution in the future...
P.S.: If anyone creates Quake maps etc from this, please post the links in this thread!