Using FileExist to check name before saving file

so change this:

        ActiveSheet.ExportAsFixedFormat Type:=xlTypePDF, Filename:= _
        "\\WDMYCLOUD\Euromatic\Invoices\" & Range("G3") & ".pdf", Quality:=xlQualityMinimum, _
        IncludeDocProperties:=True, IgnorePrintAreas:=False, From:=1, To:=1, _
        OpenAfterPublish:=True

to this:

        ActiveSheet.ExportAsFixedFormat Type:=xlTypePDF, Filename:= _
        "\\WDMYCLOUD\Euromatic\Invoices\" & Range("G3").Value & ".pdf", Quality:=xlQualityMinimum, _
        IncludeDocProperties:=True, IgnorePrintAreas:=False, From:=1, To:=1, _
        OpenAfterPublish:=True