If the column number to extract is C then
fmt = [repmat('%*s', 1, C-1), '%s', '%*[^\n]']
Now you can use that with textscan with Delimiter set to comma. You will need to convert the cell array that results into a character array.
There are other approaches including using readtable, especially after using detectImportOptions and setting the returned variables option to just the column you want.