xlswrite output numbered files

I have 20 csv files named differet names, I want to make a program to rename them so they will be numbered this way :

• M_1_1
• M_1_2
• M_1_3
• And so on ...

When I use this code :

filename_M_1 = strcat('M_1_%g.xlsx'); % g is the number of files in the directory, I put on the top of the program for g=3:length(Folders) to run the list of files in the directory
xlswrite(filename_M_1,D,1,'A1') %D is the matrix

I have a result like this :

Any ideas ? thanks for help

Answer 1

[Geoff Hayes]

Silver - try using sprintf to create your file name

 for k = 1:20
    filename = sprintf('M_1_%d.xlsx', k);
    % create new file
    % your code here
 end

[Silver]

It works ! Thank you so much !!