try something like this in column B =Sheet2!$A$1+OFFSET(Sheet2!$A$1,A1,0) where in column A sheet 1 you can have the offset which should go something like 0, 2, 5, 7 etc that way you should be able to drag the formula and 0,2,5,7 down 900 rows.
may look a bit messy and there may well be better ways to do it but it seemed to work.
Good luck
Rickity (programming)