I have tabs for each week of the year, and on each tab I need to enter a
vlookup formula to see whether the content is situated in column B on the
preceding weeks tabs.
i.e
Data in B1 on tab wk3 eq 123456. I need a formula to enter in B1 to see
whether that text is situated in column B on tabs wk1 and wk2.

That same formula will have to be used come wk52, when its has to check the
previous 51 tabs to see if data is there.

Can any on help. Never had a vlookup to do, that is this difficult