WorksheetFunction.Sum (Excel)
Adds all the numbers in a range of cells.
Numbers, logical values, and text representations of numbers that you type directly into the list of arguments are counted. If an argument is an array or reference, only numbers in that array or reference are counted. Empty cells, logical values, or text in the array or reference are ignored. Arguments that are error values or text that cannot be translated into numbers cause errors.
Sum (Arg1, Arg2, ..., Arg30)
Dim dblSum As Double
dblSum = WorksheetFunction.Sum(Arg1:=)