Function Suma(R)
Dim Celija As Object
Dim Duz(1 To 2)  As Integer
Dim FormatCelije As String
Dim a
Dim BrA As Double
Dim StrA As String
Dim S As Double


For Each Celija In R.Cells
a = Celija()
If IsNumeric(a) = False Then
MsgBox "Neispravan unos u celiji:" & Celija.Address
GoTo Kraj
End If
BrA = a
StrA = a
Duz(1) = Len(Format$(BrA))
Duz(2) = Len(StrA)
If Duz(1) <> Duz(2) Then
MsgBox "Nevalja format u celiji:" & Celija.Address
GoTo Kraj
End If
S = S + Celija()
Next Celija
Suma = Application.WorksheetFunction.Sum(R)
'Suma = S
Exit Function
Kraj:
Suma = "Greška"
End Function