You can use fopen() to open a file and then use fprintf to write to that file.
I've created a simple example:
f = fopen('test.txt', 'w')
for i=1:10
fprintf(f, "Hello: %d\n", i);
end
fclose(f)
And it looks like:
So long as you do not call fclose(), you are able to call fprintf() anywhere with f to write whatever you want to the file you've opened.
The documentation page for fprintf is here. What I've used in my example is: fprintf(fileID,formatSpec,A1,...,An), where the fileID is what is returned by fopen()
Regarding to how to save your data to excel, you can refer to this link, or you can change your code a little bit to incorporate xlswrite(), which is a function designed to write stuff to excel. Or you can write your data in csv, open in Excel, and then save it as .xls or .xlsx file
