BleepingComputer.com: text separate

Hello!
I'm having some troubles here with one text...
Let's say you've got the following words: "bleepingcomputer.com bleepingcomputer.net computer.com bleeping.org sandwich.co.uk" (just example, i don't want to advertise anything). How to separate the "*.net" words from the others? Is there a custom software, or a command in MS Word/Notepad?
Please, help me, it's important for me.
Thanks in advance!

Best Regards