If Two Cells Match, Return Value From Another Column in Excel

Question

Here is what I'm trying to return:

CustomerAccountNumber: Column C
Age of Invoice: Column D
Row Labels: Column A in a different sheet
Max of InvoiceAge: Column E in same sheet as Row Labels

Row Labels= CustomerAccountNumber 

I want to fill in Age of Invoice with the Max of InvoiceAge on the first sheet and be able to reference whatever CustomerAccountNumber and fill it in with the corresponding Max of InvoiceAge without having to go through and do it manually for each CustomerAccountNumber.

I know this is a mess but it's a continuance on from someone else's report.

Answer 1

Well, not done across two sheets, but shows both vlookup() and index() with match():