[Koha] How to add additional Z39.50 encodings

[Zac Craven]

Hello

In Koha Z39.50 servers administation I have added a new server and can 
fetch data from it.

However, it is a Japanese server and the encoding should be "EACC". Koha 
doesn't offer this encoding. If I use "UTF-8" then all the Japanese 
characters are returned as garbled text like so:

100$1i$^i$si$Si$-i$Ni$Mi$3(B / | $1i%Ri%ci%/i%^i%si%Si%-(B 
$1i%N(B $1i%Mi%3(B. | hyakumanbiki no neko.

I have followed these steps already to set apache/mysql to utf8:
http://wiki.koha-community.org/wiki/Encoding_and_Character_Sets_in_Koha

But I do not see anything in the wiki documentation about adding encodings.

This discussion seems related although there is no conclusion/solution:
http://web.archiveorange.com/archive/v/fuF7ADPjh9Qi1sG4I7HZ

Can anyone please point in the right direction to add EACC, ISO-2022-jp, 
EUC and other encodings?

Thanks,
Zac