Looking for case insensitive MySQL collation where “a” != “ä”

I’m looking for a MySQL collation for UTF8 which is case insensitive and distinguishes between “a” and “ä” (or more generally, between umlauted / accented characters and their “pure” form). utf8_general_ci does the former, utf8_bin the latter, bot none does both. If there is no such collation, what can I do to get as close as possible in a WHERE clause?