@Anonymous and anyone else who might find this useful
Attached is a maxscript which automates the process described in the above posts of recreating head morph targets after detaching a head from a combined body and head mesh. The script requires only 3 things from you the user:
1) You must set polygon material ID = 1 for the head & neck polygons of the character mesh you want to detach the head from. This is the way the script can know which polygons correspond to the head and neck. The body mesh can be any other polygon material ID -- just NOT 1.
2) The base character mesh should be an Editable poly and must be selected when you run the script
3) If you plan on running the script on multiple characters in the same scene, make sure you rename the resulting detached Head with it's morph targets (from default output of "Head_Base_Mesh") and body mesh (from default output of "BaseMesh_Body") to something unique. Otherwise, you will overwrite the morph targets on the first mesh with another morpher modifier and have multiple copies of different body meshes with the same name. I will add a safeguard against this in a future edition using some part of the existing character's name, but right now you the user are responsible for this simple step of renaming.
In my tests with a character mesh with 65 morph targets, the script took about 20-30 seconds to complete, so be a little patient. Additional details of the script are included in the .ms file which you can read in notepad or by opening the script in the Max Script Editor window.
To run the script, unzip it and drag the MorphTarget_Recreate.ms into a viewport with your character selected. Just remember that you have to first set up you material IDs as described in point 1 above so the script knows where the head is.
Hope this is helpful.