How to add latvian input language for SE W200i?

I'm new to SE customization and would like to know, if it's possible, how to add latvian input language for SE W200? I have there latvian phone language, but for input there are just russian, english, standart abc (withot needed characters) and 123.
What tools do I need? What files?
When I connect with XS++4.1 there is this information

Quote:

---

Warning: IMEI name does not match GDFS name (IMEI:W200 GDFS:n/a)
...using IMEI name
Profiling SEMC device...
Platform: DB2010
OTP CID: 51, CLOSED: 1, PAF: 1
EROM CID: 53
EROM Color: Red
IMEI TAC: 35735501
Phone ID: W200
Region: BALTIC
CDA: CDA102737/1 R1A
Firmware Version: R4JA011
EROM: n/a

---

I use Win Vista & Ubuntu 8.04.
Thanks!