Correct placement and syntax of On error go to - vba

Question

I guess this is a easy one but I can't figure it out.
I have a vba code in Excel which opens a Powerpoint presentation, find a certain type of shape ("Retângulo de cantos arredondados 9" = "Round corner' rectangle") and replace the existing text (MMM/AA) to another (TESTE).
Sub replace()
caminho_pptx = Cells(2, 2).Value
mes_ano = Cells(4, 2).Value
cx = "Retângulo de cantos arredondados 9"
Set ObjPPT = CreateObject("PowerPoint.Application")
Set ObjPresentation = ObjPPT.Presentations.Open("" & caminho_pptx & "")
For i = 1 To ObjPresentation.Slides.Count
ObjPresentation.Slides(i).Select
On Error GoTo Prox:
ObjPresentation.Slides(i).Shapes(cx).Select
If ObjPresentation.Slides(i).Shapes(cx).HasTextFrame Then
If ObjPresentation.Slides(i).Shapes(cx).TextFrame.HasText Then
If Obj + Presentation.Slides(i).Shapes(cx).TextFrame.TextRange.Find("MMM/AA") = "MMM/AA" Then
m = ObjPresentation.Slides(i).Shapes(cx).TextFrame.TextRange.Find("MMM/AA").Characters.Start
ObjPresentation.Slides(i).Shapes(cx).TextFrame.TextRange.Characters(m).InsertBefore ("TESTE")
ObjPresentation.Slides(i).Shapes(cx).TextFrame.TextRange.Find("MMM/AA").Delete
End If
End If
End If
Next i
Prox:
Next i
End Sub
The problem is that some slides doesn't have this shape, so if ObjPresentation.Slides(i).Shapes(cx).Select was not found the program have to go to the next i, but it doesn't work.
Both syntax of Prox: and its position seems to be wrong.
Any ideas?

Answer 1

You can use an On Error Resume Next statement to assign the shape to a variable, then test if that variable is not Nothing before trying to use it:
Sub replace()
Dim oShp As Object
caminho_pptx = Cells(2, 2).Value
mes_ano = Cells(4, 2).Value
cx = "Retângulo de cantos arredondados 9"
Set ObjPPT = CreateObject("PowerPoint.Application")
Set ObjPresentation = ObjPPT.Presentations.Open("" & caminho_pptx & "")
For i = 1 To ObjPresentation.Slides.Count
ObjPresentation.Slides(i).Select
On Error Resume Next
Set oShp = ObjPresentation.Slides(i).Shapes(cx)
On Error GoTo 0
If Not oShp Is Nothing Then
With oShp
If .HasTextFrame Then
If .TextFrame.HasText Then
If Obj + .TextFrame.TextRange.Find("MMM/AA") = "MMM/AA" Then
m = .TextFrame.TextRange.Find("MMM/AA").Characters.Start
.TextFrame.TextRange.Characters(m).InsertBefore ("TESTE")
.TextFrame.TextRange.Find("MMM/AA").Delete
End If
End If
End If
End With
Set oShp = Nothing
End If
Next i
End Sub