How to disable downloading of specific files (or types of files)?

[Narwhal]

OK. So I plan to add the new intelligent bots to my TF2 server:
http://www.teamfortress.com/post.php?id=3279

Part of how the bots work is that they rely on a navigation file (mapname.nav) that exists in the same folder as the map itself (../tf/maps). This file is only needed server-side, and there is absolutely no reason the clients would need it to play with the bots on the server. Unfortunately, the Valve developers have forgotten to code it out of the game engine and it tries to download it to clients (which the files don't exist on my fast downloads server so the client just sits at "downloading mapname.nav" for several seconds before finding nothing continuing to load the map). These files can be as big as several megs, so it's really something I'd like to avoid forcing clients to download. And I'd rather not have the confusion in place of the client attempting to download a file that isn't there.

Is there any way server-side to accomplish this...either through a cvar or config file or something of the sort? I've searched around and have found nothing on my own. I want the game engine to not even attempt to download the .nav files.

[hankinator]

whitelist? or something of that nature?

[lol554]

I dont think that this is possible.. Maybe with a plugin