How about running two paracord loops from the top eyelet holes. Your belt goes through the loops. Then get some 1" webbing and a pair of sliders from ace hardware. Run those through the belt slots and around your thigh. That'll put the knife under your holster level but still accessable.
The alternative is to run the 1" webbing making a loop. Run your belt through the loops and put your knife horizontally. I'd go with the first option because I'd be worried about dropping the knife.
Other choices:
Blackhawk makes some very secure sheaths if you want to spend a few bucks.
You could use the webbing to attach to your day pack and forget putting it on your belt.