The first step is to clearly lay out how you would go about doing it yourself.

Then break that description down to steps simple enough for a 3 year old to follow.

You'll want to look into opening a file, <$reading> a line at a time to get your IP addresses, chomping off the CRLF at the end of each line so you have only the IP, useing probably Net::Ping or a similar module to do the pinging for you, and then printing the results, either to screen or a file.