Java3D node centre of rotation

Been learning Java3D, it's going well but I'm having a problem with rotating models loaded into the SceneGraph.

What I'm trying to do is load the 'limbs' of a character individually from a VRML (.wrl) file and intend to animate it through code because I'm having problems loading animation from the vrml file.

All is going well, I can load each limb and they show up in the right place without needing to translate them. When I try to rotate a 'limb' they rotate around the centre of the universe (0,0,0) and I've been searching for days for a way to change the centre of rotation to another point e.g. the RightLowerArm will rotate around a point I can specify which will be the bottom of RightUpperArm (elbow).

So I've tried lot's of things to do with their corresponding BranchGraphs and read lots of the javadocs and cant seem to find a method that can change the centre of rotation, there seems to be one for a viewpoint in com.sun.j3d.utils.behaviors.vp.OrbitBehavior - setRotationCenter() but can't find anything similar for any type of node.

Any help is appreciated, thanks Mal.