Filtering in MATLAB is something very easy. Take a look at the BUTTER and the FILTER commands. Here you will find everything you need. For example, let's suppose you have your original data in the variable "signal". On a quick thought:
fs = 44100; % Sampling frequency [Hz]
order = 2; % Order
fc = 200; % Cut-off frequency [Hz]
% Create the filter's numerator and denominator.
[num den] = butter(order, fc/(fs/2));
% Filter.
signalFiltered = filter(num, den, signal);
However, are you sure your values of fs and fc are correct? It is not logic to have a cut-off frequency larger than your Nyquist frequency (that is, half of the sampling frequency). In this case, it would not make sense having a cut-off frequency larger than 22.05 kHz. Notice how in my example, fc is 200 Hz (and NOT 200 kHz).
