I bought Messiah during the Dare to Share, so not had it long myself.

I have been able to import and set up expression morphs and get them working in Messiah. There is a great video tutorial at Setuptab called 'Animated Head' which covers the steps for working with morphs in Messiah.

The video assumes you have Modo or Lightwave and can use Lightwave format 'Endomorphs' ( multiple morphs in one file ) but you really don't need that. You can import morphs into Messiah  in .obj format,  and set up sliders for them.  For simplicity the morphs need to be of the complete mesh object, and not just a part of the figure. There is a way to handle sliced up figures in Messiah, called Puppet Master but I haven't tried that yet.

Ian