Not having the PC version, I don't know if there a way to remap the mouse from camera control to movement, but I don't think so.
You could use a gamepad, though, which is what I'm planning when I eventually build a new computer capable of running D2:ED (I'm playing the Xbox version now). I'm also not a big fan of WASD movement (the arrow keys are a little better, depending on the game), and check out demos as much for the control system as for gameplay.
