DBD::SQLite can be built with ICU extension module. This enables "icu_load_collation" function and usage of collation thru ICU library. For enable this feature an additional dependance on dev-libs/icu must be setted up and following arguments must be passed to "perl Makefile.PL": CCFLAGS=-DSQLITE_ENABLE_ICU LDDLFLAGS="-shared -L/usr/local/lib $(icu-config --ldflags)"
Oh, forgot one thing: ICU extension can be enabled in described way for >=DBD-SQLite-1.24. But for older releases file "icu.c" from sqlite source tarball can be placed in addition. I think that enabling this flag for versions >=1.25 is fair enough.