while (my @res = $sth->fetchrow_array()) {
   my $c=0;
   $worksheet->write($i, $c++, $_) for @res;
   $i++;
}

##</code><code>##

COL ->    A        B        C        D        E        F
ROW -> 1 (x,y,..)
       2 (a,b,..)
       3 (q,w,..)
       4 (d,f,..)
          etc...