# pre: $guidelines is defined, HTML::Template is installed
# in your @INC and you have write privs to $filename
use HTML::Template;
my $template = HTML::Template->new ( 
         filename => "$Bin/myfilename.TMPL" );
$template->param ( GUIDELINES => $guidelines );
# now you can either print the template to STDOUT or a filehandle
# Option #1 (overwriting your .cgi file)
open ( TEST, ">$filename" );
print TEST $template->output;
close ( TEST );
# Option #2 (printing it to STDOUT - if to a Web browser,
# make sure you've already sent the Content-type ahead of
# this [next line]).
print "Content-type: text/html\n\n";
print $template->output;