It's possible, yes. You'd simply need to make sprites for all of the characters, redraw the backgrounds, remake the music in a format that can be used in a DS game format, and bring over the script. Amongst other things, because you would also need to compensate for or program things such as Athena's emotion device, which immediately throws out the Ace Attorney Case Maker, not to mention that since you'd be remaking a retail game for the DS, Capcom might take action.
But yeah, it's certainly possible.