So you need to extract a date once which appears after Sent and keep this value and use it in combination with the Analysis Date Range for each report?

open (FILE, "<" ,"datafile");
my $sent_date="";
while (<>){
       my $this_date_range="";
       ($sent_date)=/^Sent: (.*)$/; #Could be more precise, but you're
+ only expecting one instance of Sent at the start of a line ?
       ($this_date_range)= /^\*{4}\s+Analysis Date Range\s+:\s(\d{2}\/
+\d{2}\/\d{4})/;
        add_to_spreadsheet($sent_date,$this_date_range);
}
[download]

So, half way there ;) Now you need to implement add_to_spreadsheet(); Answer the questions and use the module suggested initially, it's easy enough to use once you know the steps you intend to take.