This really doesn't add up somehow. When you engage any gear, D, 2, 1 or R is there no response of any kind at all? Like a change in the engine idle? Does it act like the gear selector is not even connected to the trans? Do the backup lights work when you select R (a crude test of the PNP switch)? Does the car start only in neutral or park (another crude test)? You could engage the gear lever to its different positions while having someone watch to see if the cable moves at the gearbox.

If no response whatever it seems like the torque converter would have to be transmitting no power - and it's hard to see how that would happen unless it had burned up somehow. But never say never!