Something like this, perhaps?

#!/usr/bin/perl -w
my $crontab=`crontab -l`;
foreach (split(/\n/,$crontab)) {
  next if /^#/;
  my @arr=split(/\s+/,$_);
  $arr[5]=join(" ",splice(@arr,5)); # join the command line into a sin
+gle element
  @arr=map(/,/?"\"$_\"":$_,@arr);   # quote fields with commas
  print join(",",@arr)."\n";
}
[download]

This code has been tested, but not on animals.