I don't want to disappoint you but the old P4 hair cannot really be successfully transmapped due to the way it was modelled.  In the past there have been some attempts but the only decent ones were Allerleirauh's transmapping of the long, curly hair and Kozaburo's transmapped versions of 2 of the male hairstyles.   In fact those two seem to still be available at his site:  http://digitalbabes2.com/  check the 2nd page of downloads.   I seem to recall a very old tutorial written by him as well but I don't see that available anymore.

Well I did find it after all and it's dated 10/25/1999 !   It was actually one of the first few attempts at transmapping hair on a spherical type object so that's why it's probably not still available - being outdated and such but so revolutionary for it's time :)