ContarLetra

Public Function contarletra(letra As String, Celda As Range)
    Dim nCount, i As Integer
    Dim sTexto As String

    sTexto = LCase(Celda.Value)
    nCount = 0

    For i = 1 To Len(sTexto)
        If Mid(sTexto, i, 1) = LCase(letra) Then
            nCount = nCount + 1
        End If
    Next i
    contarletra = nCount
End Function