Gnucash language problem

[Nebojša]

I have problem with Serbian language in Gnucash, it won't work.

Is there a way to download Serbian language file and install instead 
existing file
or is there a way to fix that problem?

I try to change _*GnuCashPortableSettings.ini*_  file

[GnuCashPortableSettings]
LastDrive=E:
LastDirectory=\PortableApps\GnuCashPortable2410
Language=*_es_*


but noting happen,
for German and Spanish language work,
but not for Serbian and Slovenian.

Best regards,

Nebojša