problem biped 3ds max 8

hi guys, I have a problem with 3ds max 8. I saw that there is no Xtras. xtras allows you to add new bones to the biped .. on youtube I saw this video https://www.youtube.com/watch?v=i1FPoTnqHcY in the video we see a tool called "biped tools" which gives the possibility to convert the .bip file to all versions of 3ds max. I checked on the internet to see if I could get this scritp but I did not find anything .. is there a way to add new bones to the biped? even through a scritp or plugin?

THANKS!!