set autocommit on from a programming language

as you probably know , "autocommit" is false by default .

I want to make it true as soon as I log in from a Delphi program .
the problem is that "set autocommit on/off" is sql-plus command , so no way to call it from pl-sql procedure ,
another problem is that command ( set autocommit ) is session-dependent , so setting it from one terminal program will not
affect another terminal .

thanks