ARDUINO LEONARDO USB PC SERIAL PORT VIRTUAL AT 250KBPS

Hello everyone and thanks in advance.
I wanted to ask how I should do to communicate with a program from the pc (in c #) with the arduino leonardo via USB using the virtual serial port to 250kbps. I mean, I installed the driver that came with leonardo Arduino, I created a virtual serial port (in my case COM12), I have a C # program that opens the port and communicates well.

So far so good, although the program Buuut I open the port to 250000 and the Code of Leonardo also open it to 250000, actually opens a communication to 9600. That is work and communicate but to 9600 and is very slow for my purpose.

Anyone know how I have to do to communicate faster?
It happens exactly the same if I contact a FT232 (USB to serial converter) through virual COM port, but with the FT232 is there a library d2xx.dll that if I open a direct COMUNICACĂ“N through the library (ie without using virtual COM) if they achieve very high speeds of up to 3Mbps.

There is a similar library for arduino leonardo? or any way to get open the virtual COM port to 250Kbps??

Thank you so much