how do i tranform a txt file from matlab into a matrix (keep in mind i cant use load and save)

im making a project that involves making a menu and calculates with munkres a matrix.

the first button will be to load a certain file.txt and convert it to matrix but we cannot use load so i was thinking of asking the user to imput the name of the file and save it as a veriable and then use that variable to grab the file and convert it into a matrix.

plz help collage student in distress