It's not clear to me how you want to process the source file. Do you want one character per cell? I guess you do.

open TXT, "<", $file) or die "Cannot open $file: $!";
while(<TXT>) {
    chomp;
    my @array = split '';  # 1 char per array item
    s/\s// foreach @array;  # replace space with empty string
    ...
}
[download]

The "..." must be replaced with whatever you have to do to output the row to the CSV file, for example from the code supplied by suhailck in Re: Converting a text file to a csv file.