The Cable I used is the one from CableCreation (link). It is a 2 meter cable with nice golden contacts and a FTDI chipset which supposedly are the most capable manufacturers of Serial equipment.
The cable is detected as a 2xx chipset and so I downloaded the 2xx windows driver for the cable from their drivers page. I did install the 64bit version of the 2.12.28 version of the windows driver.
After installing the drivers, use the windows device manager and unfold the COM port section of the device tree to check which COM port is created when plugging in the cable.
In your ModelTrain-Software Package, when adding the Uhlenbrock Intellibox I, use that COM port as a connection option. Your PC should now be able to send commands via the ModelTrain-Software throught the USB – Serial Cable to the Uhlenbrock Intellibox I.
My first test was to control some of the switches and to control one of the engines. It worked just fine. As model trains tend to have hundreds of options to control, it is hard to say if every last option will work as planned for you but the first test looked promising at least.