So, you know the length of 'ch', it's 2. You know where you found it from regex, as those indices are stored in startIndex. I'm assuming (Please, correct me if I'm wrong) that you want to split all other letters of the word into single-letter cells, like in your output above. So, you can just use the startIndex data to construct your output, using conditionals, like this:
check=regexp('aachbutcher','ch');
if (isempty(check{1,1})==0) % Returns 0, when 'ch' was found.
[match split startIndex endIndex] = regexp('aachbutcher','ch','match','split')
%Now I split the 'aa', 'but' and 'er' into single characters:
for i = 1:length(split)
SingleLetters{i} = regexp(split{1,i},'.','match');
end
end
j = 0;
for i = 1 : length('aachbutcher')
if (i ~= startIndex(1)) && (i ~= startIndex(2))
j = j +1;
output{end+1} = SingleLetters{j};
else
i = i + 1;
output{end+1} = 'ch';
end
end
I don't have MATLAB right now, so I can't test it. I hope it works for you! If not, let me know and I'll take anther shot at it.