If you can't afford to purchase Microsoft Office, You can use Office Online. It's apparently free and web based. You will need a Microsoft account to use it though. Oh, don't expect them to be feature rich, especially don't count on the latest features either. (if they're there, BONUS!)
https://products.office.com/en-us/office-online/documents-spreadsheets-presentations-office-online
If your link wasn't related to the above link, it was, and is, more than likely something that could get you in trouble in more ways than one. (piracy: illegal. pirated software: potential playground for malware)
Also, as mentioned, if you need a free alternative on your computer, they exist and are probably as compatible as you need (files in...