Here's the best way to store demos IMHO:

For example for:

Name:[BWP]Shark
STEAM_0:1:19052182

The file or folder name would be:

19052182_STEAM_0_1_19052182_bwpshark_wh_p
[steamid]_[full steamid]_[name]_[type of cheat]_[posted/submitted or not]

IMSID88924469D853F488B5F0B6809FECF39E3D548CE4