How to store UTF-8 formatted characters into a UNICODE_FSS column?

Presume that i had a table with the following structure:-
CREATE TABLE TEST(
ID INTEGER,
DESC VARCHAR(50) CHARACTER ST UNICODE_FSS,
PRIMARY KEY("ID")
);

The follwing SQL statement was executed via the Interactive-SQL.
INSERT INTO TEST VALUE('1', 'UTF-8 chars');

Some of the UTF-8 characters will be store as ? or being omitted at
all.

Basically i had a tiny java program that will interface with the
database via the JDBC. After try out with MS SQL 2000, it able to
handle the UTF-8 pretty well. But when i switch to interbase 6, or
Firebird 1.0, the UTF-8 characters got fried, some go missing and
some give me question marks.

Any idea how can i do it with interbase or firebird? or perhaps any
other open source database that i can try out?

BTW, the UTF-8 characters was obtained from a UTF-8 formatted file.