If you are using Vim then use the Perl support plugin .
Or otherwise use the Autocommand in the vimrc.
Example
 autocmd bufnewfile *.pl so /home/lakshmanan/Bash/source_for_perl
source_for_perl

:insert
#!/usr/bin/perl
use strict;
.
[download]

Now if I open a new *.pl file, then the text in the source_for_perl will be there.