New custom pricing software program based off an old program we had made

Need to rebuild an old Pricing Software program we had custom made years ago (we don't think we have the original source code). We want the same exact program just upgraded to work with new versions of windows. Program uses an excel file that we already have to upgrade our prices yearly. Program will also keep a database of all customers and quotes on a network.

The old program can be found here can only install with Windows XP
https://www.floriangreenhouse.com/price.html