I have had several questions here and in my messages about the ST Commander so I took a few pics to help illustrate how I made him. Below are pics of the figures used in this project but you need 2 of the first troopers to have both feet articulated.
Next one shows that you need the AT-AT Drivers upper arms as the details on his shoulder gauntlets are the correct ones with markings at the top. Then you have to cut off the length of the swivel elbow and dremel it out for a ball hinge one from the Stormtrooper.
The Stormtrooper arm needs to be cut down about 1/4 inch and trim down the details so the glove will fit over the wrist area.
Next you cut the flared part off the AT-AT Driver glove off and hollow it out to fit over the lower arm.
Some may say why didn't you just put a peg there for a swivel joint but I wanted it to look like the armor fit down in the top of the glove. Now just pop on the snowtrooper hands and the arms are done. You could use Commander Baccara hands as well as they both have the armor piece on the glove.
Any other questions just let me know and I will try to answer them.