Since everyone else here is an ass-hole, let me explain.
The easiest program I have used for modeling is Milkshape 3D. It's not free, but you can use a demo for 30 days with the same features as the full version. You can make a model, and add joints, then export it to DTS.
The script is a part that I doubt you will be able to get on your own. The only thing I can recommend it copying an add-on from the Add-ons folder, and change some stuff in the "Server.cs" file. Use notepad to open it.
I don't want to teach you how to script, and you should probably consider looking up "Torque Script" or something. Maybe there is a website that will teach you about it, and how to use it.
Scripting is difficult, and I wish you the best of luck.
There is no up-to-date tutorial for making Add-ons, so you'll have to figure it out like I did.