new bath drain connection --- help!

I removed a bathtub and now I'm ready to install a new tub and new drain. The drain pipe that I have access to is 1.5" thin metal, like something you might see under a sink. It was threaded but apparently when removing the old tub, I damaged the threads. I've attached a picture (hopefully), which isn't very good, but should make it a little clearer.

I really really really don't want to rip up the floor, so my question is, how can I securely attach a new pipe/drain to this? I've only got about an inch or two that I can reasonably access and even that is below the level of the floor. Thanks.

What you have described is a tubular size brass tailpeice which is part of the waste and overflow kit. You will need to get down to the actual drain pipe and start fresh from there, It will only be 2" lower than the tubing that you have already exposed.

followup questions

OK, I might be able to do that, but how would it be attached at the "2" lower" point, and what do I need to do to remove it, and what should I then attach? Thanks.