A dos command problem

the code below does not work in Matlab but when I execute it in cmd window it works. why?

command=[dir(1) ': & cd "' dir '" & "' filename '.bat"'];

err=dos(command);

Answer 1

[Image Analyst]

I already gave you the solution in your duplicate post:

https://www.mathworks.com/matlabcentral/answers/1649405-error-when-calling-dos-error#answer_895875