Pass Multiple Non-contiguous Ranges Into A User Defined Function

I am trying to call a function that calculates forecast error (wMAPE). This function needs to be able to handle passing in non-contiguous ranges. I can't seem to figure out how to do that.



Function wMAPE(Forecasts As Range, Actuals As Range, Weights As Range) As Variant
Dim Denominator As Double
Dim Numerator As Double
Dim i As Long
Dim Fcst As Variant
Dim Act As Variant
Dim Wt As Variant

If Forecasts.Cells.Count Actuals.Cells.Count Then MsgBox ("Error: Arrays not same size")
If Forecasts.Cells.Count Weights.Cells.Count Then MsgBox ("Error: Arrays not same size")

Denominator = 0............