I don't use this method too often but I have a lazy way of doing this, I don't know if it's necessarily the 'right' method, but I use 'FOR' :
system(for) "name" from enemy.IID to enemy.IID > pin bazooka to enemy.
This matches up the IDs, so first instance of bazooka would pin to first instance of enemy, second instance of bazooka pins to second enemy etc
Also note that this will still mean that they are floating in the air from their current position, you'll have to also add : set bazooka position to enemy.x,enemy.y, to teleport them to the enemy position (unless they were created at enemy position of course).