How to install a freestanding tub next to an existing shower?

[helios]

Hey plumbing pros - I would like to install a freestanding tub where my existing closet is, adjacent to a very large walk in shower. I know I should make a hole in the concrete and tie the tub drain in to do this right, but is there another way to install this tub, such that it drains into the existing shower plumbing, without making a hole in the concrete? for example, could I put the tub on a raised platform and run a drain into the pain of the shower thru the wall (I know, probably not legal nor sanitary and super ghetto)... or another way? thanks