I don't have C2, so I can't advise, but where is the tutorial? If you search this forum's old messages, there are some descriptions and examples of how to do Poser eyebrow, eyelash, eye and hair transparency in C1 using mixers, dating back to a message from Antoine Clappier in 2000:
" In Carrara, you would:

• Create a shader that define the texture of your object (color, shininess,
  etc)
• Create a 100% transparent shader
• Mix the two using a multichannel mixer and put the texture map in the
  blender."