Gravity Gun

I was wondering if anyone has the know how to alter the Gravity Gun (from an early T3D demo) to pick up a single PhysX object, hold it, and allow you to put it back down (similar to Portal). Currently, it acts like a suction machine and just pulls PhysX objects towards the player and kind of throws them away. Thanks for reading!

// GravityGun weapon.

function GravityGunImage::onFire(%this, %obj, %slot)
{
   //echo("WeaponImage::onFire( "@%this.getName()@", "@%obj.client.nameBase@", "@%slot@" )");

   // Gravity Gun has infinite "ammo".
   //%obj.decInventory(%this.ammo, 1);

   %vec = %obj.getMuzzleVector( %slot );
   %start = VectorAdd( %obj.getMuzzlePoint( %slot ), "0 0 0.2" );
   %end = VectorAdd( %start, VectorScale( %vec, 100 ) );

   %impulse = "0 0 0";

   %hit = castForceRay( %start, %end, %impulse );
   if ( %hit !$= "" )
   {
      %impulse = VectorScale( %vec, -15 );
      castForceRay( %start, %end, %impulse );
   }

   return "";
}