How to fetch the record that have the closest date?

Here is the excel raw data example

• StaffID Date Accumulative Balance
• s15 15/12/2015 31
• s15 31/12/2015 64
• s15 3/4/2016 65
• S98 13/4/2016 65
• ......

Now i want to generate a report in excel . This report i have to show every staff starting accumulative balance from 1/1/2016-31/3/2016.

Starting accumulative balance refer to the accumulative balance before 1/1/2016 .

For example , for staff S15 ,the balance should be 64 (most closest Accumulative Balance before 1/1/2016 .

Any function useful in this case to get the closest date record ,so that I can fetch that record field(Balance).

Btw, the starting date (1/1/2016) should be stored in a datetype variable-startdate