Create a sumproduct function in vba

[EliSilver]

Hello, I need to make a sumproduct_if function in vba, but I really don´t know how to start.

This is what I have:

Function SUMAPRODUCTO_SI(rango_1 As Range, rango_2 As Range, rango_cond As Range, condicion As String) As Double

Dim filauno As Integer, columnauno As Integer, filasuno As Integer, columnasuno As Integer
Dim filados As Integer, columnados As Integer, filasdos As Integer, columnasdos As Integer


Dim valoruno As Double
Dim valordos As Double

Dim multiplicacion As Double

Dim acumulado As Double

'Encontrar la primera celda del rango uno y del rango dos

filauno = rango_1.Row
columnauno = rango_1.Column
filasuno = rango_1.Rows.Count
columnasuno = rango_1.Columns.Count

filados = rango_2.Row
columnados = rango_2.Column
filasdos = rango_2.Rows.Count
columnasdos = rango_2.Columns.Count

For i = filauno To filauno + filasuno - 1
For j = columnauno To columnauno + columnasuno - 1
valoruno = Cells(i, j).Value
For m = filados To filados + filasdos - 1
For n = columnados To columnados + columnasdos - 1
valordos = Cells(m, n).Value
multiplicacion = (valoruno * valordos)
acumulado = acumulado + multiplicacion.Value
Next n
Next m
Next j
Next i

SUMAPRODUCTO_SI = acumulado


End Function


Please, If someone can help me...¡thank you!