plPerl subroutine

hi

is it possible to create subroutines with plPerl ?

i tried this :
CREATE OR REPLACE FUNCTION adoc.CREATE_XML_FILE(docId int4, eleId int4, evo
int4, fileName text, fileRelativeDir text)
RETURNS int4 AS
$BODY$
my $theClob='';

my $params = 'select
adoc.GET_XML_FRAG('.$_[0].','.$_[1].','.$_[2].',\''.$theClob.'\','.0;
$params = $params.')';

$theClob = spi_exec_query($params);
elog NOTICE, $theClob;

return 4;
$BODY$
LANGUAGE 'plperl' VOLATILE;

CREATE OR REPLACE FUNCTION adoc.GET_XML_FRAG(docId int4, eleId int4, evo
int4, clob text, indx int4)
RETURNS text AS
$BODY$
my $t_clob = $_[3].'totototototototototot';

return $t_clob;
$BODY$
LANGUAGE 'plperl' VOLATILE;

but the CREATE_XML_FILE doesn't display 'totototototototototot' but
HASH(0xf03fa4)....

is it possible with this solution or does i need to create a module
(including makefile, .pm, ...) ?
if i must create a module, can you explain how to do ?

thanks