gbarco:

Given your proposed usage, then I'd use XML, as mentioned in earlier posts. That way, you'd be able to:

1. produce your template easily (generate it manually, or create a spreadsheet in Excel, save as .xlsx and edit it into shape),
2. fill it out without jumping through flaming hoops (text files are *much* easier to munge, and XML files may be even easier with the various XML packages available on CPAN),
3. and be able to have widespread usage. (Since XML is easy enough to read and manipulate, people using tools other than Excel may be able to use your files.

Of course, that's just my $local_currency/50...

...roboticus