Append a cell array to an existing CSV file

I have a script that strips a block of data from an input file, does some reformatting, and writes that output to a new CSV file.

I have a mountain of input files, so I've also created a log file that keeps track of what files have already been processed, as well as some useful information about them. In order for the log to be useful I need not just the numerical data, but also the input filename. The script I put together writes the numerical data to the log file:

dlmwrite('LogFile.csv',M, 'delimiter',',','-append'); %Append values to file

But I then have to open the log file, type in the input file name, save it and close it before I can run my script again.

The log data is in a 1 by 13 cell array in which the first 12 values are numerical and the final value in the input file name.

I've been generating the cell array that has all the values I need using the code below:

for i = 1:12 %creates data to append to LogFile
    LogData(1,i) = {M(1,i)};
end
LogData(1,13) = {filename};

When I try to append the cell array using dlmwrite I get the following error:

 The input cell array cannot be converted to a matrix.

I've tried fprintf as shown below but that "Function is not defined for 'cell' inputs."

fid2 = fopen('LogFile.csv', 'a+');
fprintf(fid, '%s %s %s %s %s %s %s %s %s %s %s %s %s\n', LogData);
fclose(fid);

Any thoughts are appreciated.

Thank you,

RS