UniBox Excel software on recent systems

I loved the unibox excell software for designing and comparing bass speakers:

http://audio.claub.net/software/kougaard/ubmodel.html

I'm having a lot of trouble trying to make it work on recent OS system. It doesn't work with Office365 pro cloud account, same issues with excel for MacOS. I had to install a Windows 10 with an old version of MS Office under virtual box with all the associated woes.

The software is also password protected so I can't just make any mods to it. Do you have any hint to make it working properly on new OS? Can you suggest another software of similar quality?
 
I tried we the latest version of Libre Office, I confirm that Calc loads the file, but most functionalities don't work.... It's a pity because that one is a very good software for bass response. I'm not a visual basic expert otherwise I wonder how difficult would be to port that simulator in Python (for example).
 
ah ok you worote Open Office but I read in the back of my mind Libre Office 🙂

I don't have an Open Office installed I should give it a try. But, could you try to do something like changing a parameter and update the plots with the button to see what happens?