SQL & PL/SQL

Hello, I am working on a new project using the UTL_FILE utility in oracle 11g. and I was wondering if someone could help me with some pl/sql code I can't figure out.
My goal is to open and and read from a file1.txt file_type then
copy a specific paragraph from that file1.txt where
the first word in a specific line in the file1.txt begins with 'foo' and where the last word in file1.txt ends with 'ZEN' Then
write to file2.txt only the parse section in my where statement.
I am not sure if this is possible but any guidance will be greatly appreciate!

My example code:

CREATE OR REPLACE PROCEDURE my_app2 IS
InFile utl_file.file_type;
OutFile utl_file.file_type;
buffer VARCHAR2(30000);
BEGIN
-- open a file to read
InFile := utl_file.fopen('TEST_DIR', 'mytst.txt','r');
-- open a file to write
OutFile := utl_file.fopen('TEST_DIR', 'out.txt', 'w');

-- check file is opened
IF utl_file.is_open(InFile) THEN
-- loop lines in the file
LOOP
BEGIN
utl_file.get_line(InFile, buffer );
--write to out.txt
utl_file.put_line(OutFile, buffer, FALSE);
utl_file.fflush(OutFile);

EXCEPTION
WHEN NO_DATA_FOUND THEN
EXIT;
END;
END LOOP;
END IF;
utl_file.fclose(InFile);
utl_file.fclose(OutFile);
EXCEPTION
WHEN OTHERS THEN
RAISE_APPLICATION_ERROR (-20099, 'Unknown UTL_FILE Error');
END my_app2l;
/