I forgot where but i'll look in a little bit but your bow ID lets say is 500349
Now link 500349 to the super arrow effect (Client folder\c3\effect\arrow\FIND THE ARROW YOU WANT)
Which would be the .dds and .c3 files.
Until I can get back to you on where to put it (I'm really busy right now) someone else might be able to help or just search your ini folder.