Animation Retargeting - Graphics software

I am looking for someone good at math/linear algebra. I am developing skeletal-base animation software, and one of the planned features is to retarget a skeleton from one 3d model to another. Check attached picture to understand, the picture displays a 3d model, and two skeletons (overlapping). One skeleton is in normal bind pose, the other is display a running animation. Both skeletons have different number of bones. The objective is to write an algoritm that applies correct translations/rotations from the running skeleton to the other skeleton.