dlmwrite function - strings in matrixes

Question

Am trying to write a *.txt file with 3 different matrixes (same number of rows). I am using the dlmwrite function but it doesn’t work with one of the matrixes, which is composed by strings (names of input files). I am getting an output where the strings are split into characters. Why is this happening? How can I solve this problem?

dlmwrite ('C:\file.txt, [output_strings output_1 output_2], 'precision', '%.2f','-append','newline','pc','delimiter','\t')