Excel 2007 : Need to match data and find missing

Hi, i am a user on a Paid to Click site and i try to maintain data on how my referrals click on a spread sheet. Im having problems using the ISNA and the VLOOK UP formulas. I import data from the site that im using everyday. Some times referrals which do not perform get replaced. So, in my sheet i want to find out the referrals which have been replaced.

I have been searching on google on how to solve this problem and i still haven't been able to understand these 2 functions.

I have 2 sheets namely "input" and "daily clicks". The input sheet is where i import data daily from the site. The daily clicks sheet is used to record the referrals performance.

I want the "missing" or "replaced referrals" to show up on the daily clicks sheet after i import the data in the "input" sheet.

The "referral since" column is sorted as per Oldest to Newest. And the "referral id" column is sorted "A to Z".

Currently, the data in the input sheet is of the date 3rd april. This is the data i want to add to my daily clicks sheet where in the missing referrals will show up.

I have attached a copy of my sheet so u can understand better.


I hope im not troubling you guys and i hope u can understand what i have tried to explain :D . Any help will be highly appreciated! thanks!