With version 8.0.2 your only option to get accented characters to be treated as unique would be to use the dbcollat utility and create your own custom collation based on 1252.
You can find info. in the 8.0.2 help file under "custom collations" and the "dbcollat" utility. Basically, you can unload the collation from a 1252 database and then customize it to your liking and use the customized location when you create a new database.
However, note that custom collations have been removed in more recent versions of SQL Anywhere in favor of the more standard ICU collations, so if you do upgrade in the future, you will have to rebuild your database with a new standard collation.
--Jason