The empty should work....basicially the game goes through and any 'frames' that dont contain vertex data (ie: they're just position and scale information) will be interperated as a hardpoint.

Also, as far as naming goes, thy don't even need to be called "Dummy"...any name can be used. However, if you name them with the following prefixes, they will be used in the following manner...

P0, P1, P2, ect: By naming the hardpoint with a P as the first letter, it becomes a "Propulsion" hardpoint (if the player auto-places an engine, it will attached to one of these hardpoints)

W0, W1, W2, ect: Same as above, only for weapons.

E0, E1, E2: these hardpoints will be hidden in-game, but during fleet battles engine exaust will eminate from these point.

Hope this helps!