I was wondering if there is a formulas where I can do vlookup on multiple
changes.
I have a list of unique number and they can change a few time within a year.

For example I have a list of change on sheet 2 as follow:
Old # New #
1 10
3 5
4 7
10 15
15 20

If there a formula where I do a vlookup for 1, it will return 20 in stead of
10.
The logic the original 1 had change a few time and the final number i should
use is 20. At the moment, I have to use multiple columns to get to the number
20.

I need a formula where it will lookup for a number and the do another
vlookup on the new number and see if there is anychange. And if there is, it
will do vlookup until there is no more changes.

Thanks.