Need to send email to user on expiry date to return book

hi there....

i have been seacrhing and trying to do code for attached excel file and cannot figure out how it will work ....

i need that when there is 5 days left from a period of 30 after issuing the book ...an automated email gentred to that person in list and row is being highlighted ... and email should also cc to libriyan ...... and email also should repeat it self every 5 days intreval until its retun back...


please help i have done some coding but its not working ...... thanks for your help and support

HI this is my frist post to forum .... hope to get any response soon.... thanks