Is prepared cursored query possible?

Hello folks,

I'm improving the capabilities of the JDBC driver of Postgres at the moment;
only one problem:
I tried to "declare curs_4711 cursor for execute prep_0815;" and get an error
message for the execute inside the statement.
As I refer to the docs, they say only select is possible, which seems illogical
to me. Is that intended or just a parser inability/grammar inability?
Or is there a workaround for that? (maybe a select from ... thingy?)

tia

Patric