Essentially, you're going to need to eavesdrop on the communication that is happening between the software and the USB dongle and write a device driver that emulates that conversation.
I can't say how difficult this will be in reality, it depends on how that data is exchanged. Complicated encryption schemes could make it insanely difficult -- if it's just handing over static data each time, -- insanely easy.
Feel free to private message me if you'd like to discuss it further, or add further details to the project description if possible.