I have a spreadsheet that has 5 columns
Sheet 1
Col 1 = Identifier (1,2,3,4..etc)
Col 2 = Date
Col 3 = $$
Col 4 = $$
Col 5 = sum cols 3 & 4.
Each row is a new record, approx 2000 records

Sheet 2
Is a lookup sheet where the identifier is keyed in and presents the data in
sheet 1 for the particular identifier in a "pretty" format.

Sheet 2 is also used to update Col 3 & 4 in sheet 1.

My question is how can I enter values into cells on sheet 2 that will update
the respective record on sheet 1.

any help much appreciated.