More linux struggles. I am in over my head

Ubuntu 14.? is installed on a Dell machine and works great, but no driver for the Serial port, which is how HRD communicates to the Radio. so no-go.
Next I bought a usb-Serial adapter cable, and while Ubuntu sees the cable, HRD running under WINE does not see it as a COM port option .
My next thought is to buy a Serial Card with Linux Drivers and cross my finders.
Otherwise, I may have to use an antique XP machine, that I really dont want to.
Oh and I dont have any Windows software to load to the machine, to make it a dual boot machine.
Any body have any thoughts? I dont do 'wrappers' or Kernels

Over my head,
Kevin