Depends on what physics engine you are using, Newton or ODE?

If you are using newton, I found this code in one of my old projects:

Code:

---

var toss_speed=100;//push speed and force
var toss_force=25;
var react_dist=50; //player pushes objects closer than this distance


action NewtonBox()
{
	
	.....
	
	var body;
	while(1)
	{
		body = NewtonGetBody (my);
		if (body)
		{
			if(player) //if player exists on the level
			{
				if (vec_dist(my.x,player.x)<react_dist)
				{
					newtonImpulseRecord[0] = my.x;
					newtonImpulseRecord[1] = my.y;
					newtonImpulseRecord[2] = my.z;
					
					newtonImpulseRecord[3] = player.x;
					newtonImpulseRecord[4] = player.y;
					newtonImpulseRecord[5] = player.z - 0.25;
					
					newtonImpulseRecord[6] = toss_speed;
					
					newtonImpulseRecord[7] = toss_force;
					
					NewtonBodyAddImpulse (body, newtonImpulseRecord);
				}
			}
		}
	}
}

---

I cannot remember how good it worked, but it should get you started

Thanks,
Adoado