3ds Max Animation :: Transfer Weight Map Between Bone

I have an old figure that is high poly and skinned to a bone skeleton. I want to rig it to a CAT rig for some of its quick animation features. Ultimately I want to be able to export the model into UDK to learn 3d demonstration and game development.

I have aligned a CAT rig to match the bones of the old figure. If I select and link the bones to the respective bones in CAT rig I can get the figure to animate perfectly and quickly, but when I export to the UDK through FBX the figure is severely distorted. I've found that the old rig needed to match the rotational axis order to the new CAT rig bones which worked a little on several of the limbs, but the initial translation of each bone does not get transferred giving an offset to the bones that still distorts the figure.

I want to rig the character with the CAT, but the figure uses painted vertex weights. I could spend an immense amount of time to try and replicate the quality done by the vertex weights, but if there is a tool or script that could speed up the process. I am looking for a tool that would be able to transfer vertex weights between bones. Ideally I'm looking for a workflow like so

1. Load figure
2. Add CAT bones to skin
3. Edit envelopes
4. Select bones or vertexes to copy
5. Copy vertex weights
6. Select bone destination
7. Paste vertex weights

The paste should then delete the influence on the original bone to complete the process.

I've seen something very similar to what I've been needing from this artist that goes by the name of Sun Dawei. A search for "Dawei Sun transfer vertex skin weight" minus the quotes gives you a video that would visually show the process I'm looking for. I don't know the policy on putting links for videos that I don't own so I won't put the actual link here.

I would like the script that Sun Dawei developed, but I could not find a download for it. He might have wanted to keep his work private, so I'll respect that.