DSiWare requires certain software to run. This software doesn't exist on DS Phat or Lite and therefore you cannot whatsoever run DSiWare on anything other than having a DSi.
Furthur more there are no "ROM" (wouldn't they be WAD like WiiWare?) of this or other DSiWare games because there is no point at the moment. The hackers haven't worked out a way to make it so they can be installed on a DSiWare.
There were some DSiWare games dumped a while back, but like the early WiiWare dumps these probably wont work if someone did release an installer to install the games onto a DS.
So yeah, you can't play pirated DSiWare games on anything right now. I dunno if when this system is hacked that someone will work out a way to get these to work on DS handhelds other than the DSi because I have no idea about how these things work (maybe there are hardware reasons) so for the time being just accept that you can't and move on with your life.