aggregate array average blank chart columns condition conditional format conditional formatting copy count countif data data validation date dates duplicates dynamic error excel excel & formula excel 365 excel formula excel vba filter formula formula and functions formula assistance formulas formulas & functions function functions graph help a dummy hstack index index match indirect introduction lambda list lookup loop macro macro (vba) macros match password pdf pivot pivot table power query rows search solver sort string sum sumif sumproduct table tables time unique userform vba vba & excel vba & macro vlookup xlookup