Therein lies a bit of a rub - you might be able to find the RS USB cable (original SKUs were 20-047 or 20-546) on Amazon or eBay, and they may have the drivers on their website. If not, we have the FTDI drivers in the Aftermarket section of...
Connecting scanners via USB - The RadioReference Wiki
I'm not familiar with these aftermarket suppliers, so caveat emptor. If there are better suppliers of the RS USB cable, then let's have it.
Be sure to get the right version of the drivers - Windoze has gotten picky about issues with unsigned drivers and the like. Drivers for Win 8.x will also likely work with Win10
GL...Mike