Probably only models with High Collision LOD can be bullettraced. Maybe make e.g. a sphere in Maya, export it with High Collision into CoD2 and just link that sphere to every player.

PHP Code:
player.sphere createSomeTransparentSphereAndLinkTo(player);
player.sphere.player player
When bullettrace hits the sphere, you can access the player entity via trace["entity"].player

High Collision LOD in Asset Manager: https://killtube.org/showthread.php?...ull=1#post9426