Well, you can create a button callback, where you can write a simple code. See the code below:
A = [12.7 5.02 -98 63.9 0 -.2 56];
[file,path] = uiputfile('*.xlsx');
filename = fullfile(path,file);
csvwrite(filename,A);
It actually gives an answer directly to your question. The thing that will change is that your A matrix will come from your app. Try to adapt this code into your app and let me know the results.
