Hi Wallyhorse, I had to Google ‘paradox dos’ to work out what you were referring to. I assume you are talking about the database?
DosBox has a small tidbit of information on Paradox.
http://www.dosbox.com/wiki/Software:Paradox_4.0
Otherwise you can run DOS on any modern computer using VMWare Player or Oracle VM VirtualBox. There is a bit of a learning curve for first time users of virtualization but that would be your best bet to start.
http://www.vmware.com/products/player
https://www.virtualbox.org/
You will also need a copy of DOS to use with either software. FreeDOS would be your best bet if you don’t have access to MS-DOS or PC-DOS. http://www.freedos.org