The actual mechanics of the game do not lend themselves to gamepad input. While many games DO work well, even better, with gamepad input (the majority these days) DOS is not one of those games. What you're suggesting is akin to requesting gamepad support for Baldur's Gate II, or Starcraft.
If you absolutely have to play the game one-handed... well, you can. You can play the game entirely with a mouse.
If you can't use a mouse comfortably, well, you probably shouldn't be gaming on a PC, but you could always get a nice trackball and just set it down in your lap or wherever. Or you could use a middleware program like Rack suggested.
