Hmmmmm. IMHO anyone who uses multiple dots in a filename deserves to get messed up. That is just poor naming.
Interesting. We do this a lot as a technique for 'relating' files

For example, 'Proposal for Bill.xlsm' will generate 'Proposal for Bill.data.xlsx' and 'Proposal for Bill.backup.txt' and 'Proposal for Bill.OfferLetter.docx' and 'Proposal for Bill.MgtCopy.docx' all in the 'Proposal for Bill.xlsm' folder

Paul