If I understand you correctly, BitComet already has this, they are called “tags”, click on the tags icon and the menu will appear, then go to “tools” and “options” and setup what ever type of tags you want, then you can assign any tag to each torrent and sort them.
Isn’t this exactly what your asking for?
If on the otherhand, you are wanting bitcomet to automatically know what the download task is and put it in the proper tag for you, then that is not possible, there is no such identification built into bittorrent protocol.
I’m aware of the tags option, I believe the tab feature would be a bit more practical, especially when dealing with large number of files and a high turn over rate (removal of completed downloads and addition of new ones). Regarding automatic placement I’m aware that’s impossible the tab names where just examples, the user could name them what ever they want during creation.