I want to use vlookup to pull data from one sheet to another. The sheet I am
pulling data from has numerous results(one for every day). I want to average
those results. So for example I want to use the following formula for all the
days and give me the average.

=VLOOKUP(B6,Logging!B4:K69,10,TRUE)

I need it to take the results from column "B" minus column "C" then divide
that info by column "A" and use vlookup to pull that answer and give me that
average on the second sheet.

Any ideas on how i can accomplish this?