One way would be to make use of a function:
foo() {
sqlplus -s/nolog $USER/$USER@BRMDPP <<END
set pagesize 0 feedback off verify off heading off echo off;
SELECT ...
exit;
END
}
and later invoke it by saying:
value=$(foo)
In order to get the value returned by the function, say echo "$value"
(note that quoting variables is important).