I have thought about your question for a while. I believe the easiest route
to go would be to write a macro that just simply copies and pastes a Vlookup
formula into cells AL:BA into the sheet every quarter. That way, you are
guaranteed to have 5,000 records before and after, and not have to do any
copying or writing of formulas by hand. IT should be pretty simple. Let me
know if you need help with this.

Kou

exp: (Similiar to this code)

With Worksheets("Original").activate
range("al2").forumla= "=vlookup(b2,'quarter!'al2:'quarter!'ba2,1,fal se)
range("al2").select
selection.copy
range("am2:ba2").pastespecial xlpasteformulas
Application.cutcopymode = false
range("al2:ba2").select
selection.autofill destination:=range("al2:ba5000"), type:=xlfilldefault
end with