Encrypting a Message with secret code?

I need help encrypting a message with code. Instructions are in the document attached. Heres the code I have so far:

s ='MATLAB'
val=double(s)
nume=reshape(val, 3, 5)
m = [1 5 3; 2 11 8; 4 24 21]
%inv(m)
nume=nume-32
ncoded=mod(m*(nume),95)+32
scoded=reshape(char(ncoded),1,15)
%sdecoded = reshape(double(scoded),3,5)
%ndecoded = mod (inv(m)*(sdecoded-32), 95) + 32
%sdecoded = reshape (char(ndecoded), 1, 15)

Answer 1

[TastyPastry]

There are tons of Caesar Cipher resources out there since it's a pretty basic problem in computer science courses.

Here's a completed example