Oscilloscope to Matlab to Arduino

I need to connect an oscilloscope, Tektronix TDS 2014, to MATLAB and run the signals to operate an Arduino. The LED lights on the Arduino need to turn on and off according to the current on the Oscilloscope. I am concerned about a possible lag in the speed, so I am seeking to create a buffer through an excel file. The excel file should synchronize the values from the oscilloscope and send it to the Arduino. So for certain range of values the LED on the Arduino will turn on, and for others it will turn off. What is the best way to do this?