Once your data is in @file why not something like this:

my ($row, $col) = ("A", 1);
for (@file) {
  $Sheet->Range($row.$col)->{'Value'} = $_;
  $col++
}
[download]

Of course, this only handles one row. You can increment through the rows as well, using the automagical ++ incrementer on $row. BTW, when you have delimited files you should be thinking "split/join" and if you have fixed-width files you should be thinking "unpack/pack". Regex's should be your last choice in those situations. :-)