money type

Is there any config setting that can make queries like

Select * from money_field where cost > 25

be valid in postgreSQL? I guess not, but just want to make sure. Since I
want my code to stay the same between Access, Oracle, and postgreSQL,
that leaves me only one option (suggested by docs too): convert currency
types in other DBs into numeric in postgres.

P.S. I guess I don't have an option to select numeric(10, 2) or the like
in pgAdmin, however. It has to be just numeric... Am I right? Is it
possible to alter table afterwards?

Thanks,
r.