Well, there is the touche.. a little pricy though
https://www.expressivee.com/touche-se
There are a lot of other little controllers, might do the job. Or you could just get a windows mod wheel application, I am sure there are some (I don't use a PC for midi so not sure what is around).
Unfortunately this is just the disadvantage of progress. Back in the day devices just had 5 pin midi ports - if you had two devices and one had an in port and one had an out port, you could connect them, and they would do 'something' whatever that was. This is still the case for old midi, but if you want to use USB, it has a direction, one end if a computer, the other end is a thing being controlled. A controller can't connect to a controller, and a computer can't connect to a computer.
You could use a bluetooth midi device, yamaha make one (i have it), which you could connect a computer to an ipad (which uses bluetooth midi). That would almost certainly work.