how can i read letters from an input and make them numbers to make an array from those numbers

i want to make a program in which i need to select depending a cordenate that is in fact a letter like AB,BC,CD...etc but i dont how to make it or if even possible. (my english its not that good my bad)

Answer 1

[Walter Roberson]

ValidInputs = {'AB', 'BC', 'CD', 'DE', 'AD'};
INPUT = input('enter some letters', 's');
[found, idx] = ismember(lower(INPUT), lower(ValidInputs) );
if ~found
    error('invalid input');
end
selected_case_idx = idx;
selected_case = ValidInputs{selected_case_idx};

Answer 2

[Image Analyst]

Try this:

validInputs = {'AB', 'BC', 'CD', 'DE', 'AD'};
selectedIndex = listdlg("PromptString",'Select an option', 'ListString', validInputs)
fprintf('You selected index %d which is %s.\n', selectedIndex, validInputs{selectedIndex});