Assuming all the records in Book1 are found in Book2, you can do this with an array formula. For example, with both workbooks open, the following will update column B:
=INDEX([Book2.xlsx]Sheet1!$B1:$B10,MATCH(A2&C2&D2&E2,[Book2.xlsx]Sheet1!$A1:$A10&[Book2.xlsx]Sheet1!$C1:$C10&[Book2.xlsx]Sheet1!$D1:$D10&[Book2.xlsx]Sheet1!$E1:$E10,0))
For column F, change '$B1:$B10' to '$F1:$F10'. Also, assuming you have more than 10 rows, change all the 10s in the formulae to whatever is the maximum nuumber of rows in Book2.

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Cheers,
Paul Edstein
[Fmr MS MVP - Word]