A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
You can either use VLOOKUP or, if you will be returning multiple columns of data for the same reference number, use MATCH to return the position of the relevant data on sheet 2 and then several INDEX formulas to pull the data.
So, let's say Sheet1 has the reference numbers starting in A2 and down, and SHeet2 has the reference numbers in column A and other data in columns B:H that you want returned to sheet1.
In say B2 on Sheet1, enter:
=MATCH(A2,Sheet2!A:A,0)
This will return the row number on sheet 2 where the reference number is located. Then in C2 you can enter:
=INDEX(Sheet2!B:B,$B2)
to return the relevant data from column B on sheet2. Copy this across and you will get the relevant data from column C, D and so on.
Does that help?