Problems with encoding

Hello, I have a trouble with encoding iso-8859-13 (Lithuanian). At first there are problem with fontifying text. For example, I edit HTML text (html-mode). Everything is ok except I can't see Lithuanian characters (iso-8859-13) in bold, italic - symbols are in shown in latin encoding (althgough they are saved ok) - other lithuanian symbols are shown good. Another problem - input of lithuanian symbols. As I noticed there is iso-8859-4 encoding in mule, but here we use iso-8859-13 encoding in Lithuania, so I can't save lithuanian symbols. Entering symbols is ok (I use xmodmap, encoding iso-8859-13), but when I try to save document I get bad symbols (as iso-8859-13 is not supported). How culd I solve these problems? Thanks, Saulius