This shouldn't be a big problem in Matlab code. The most work is in defining input signal. Here's one example:
close all
clc
num = 0.5;
den = [20 1];
% Create transfer function
G = tf(num,den);
t = 0:0.01:50;
% Creting pulse:
u = ones(size(t));
u(t >= 20 & t < 40) = -1;
% Simulate
y = lsim(G, u, t);
subplot(211)
plot(t,u)
subplot(212)
plot(t,y)
