ahhh.really u have to use pl/sql code..wonder

try this:

c:\>rman target sys/password@service_name
rman>backup format 'c:\oracle_%U' database;

just a simple way of taking hot n full backup..one backup piece..
choose format as u wish..
allocate channels for parallelism..
limit max set size..
limit maxpiece size..
limit maxopenfiles..
autobackup of controlfile n spfile..


many other options r there..read sm oracle docs..just google "rman backup and recovery"