The demos actually use a skinned mesh for the visible hands and weapon, but here is a tutorial on skinning and animation:
Article:
http://www.leadwerks.com/files/Tutorials/CPP/Introduction_To_Animation.pdf
Video:
http://www.leadwerks.com/files/Tutorials/CPP/Introduction_To_Animation.wmv
Article:
http://www.leadwerks.com/files/Tutorials/CPP/Introduction_To_Animation.pdf
Video:
http://www.leadwerks.com/files/Tutorials/CPP/Introduction_To_Animation.wmv