You can read the file and delete these rows like this
f = fopen('04.txt');
data = textscan(f, '%s', 'Delimiter', '\n');
fclose(f);
data = data{1};
rowsToDelete = startsWith(data, {'F', 'N', 'D'});
% rowsToDelete = cellfun(@(x) any(x(1) == 'FND'), data); % for older version than R2016b
data(rowsToDelete) = [];
the variable data will contain all the remaining rows as char array. Since all these rows contain mix datatypes i.e. characters and numbers and a variable number of elements. it is not clear how do you want your final data in the numeric form.
