=ПОДСТАВИТЬ(A1;".";",")

=ЗАМЕНИТЬ(ЗАМЕНИТЬ(A2;ПОИСК(".";A2);1;",");ПОИСК(".";ЗАМЕНИТЬ(A2;ПОИСК(".";A2);1;",");ПОИСК(".";ЗАМЕНИТЬ(A2;ПОИСК(".";A2);1;","))+1);1;",")

Function ЗАМЕНАТОЧКИ(myString As String)
         
     Dim objRegExp   As Object
     Dim objMatch    As Object
     Dim colMatches  As Object
     Dim RetStr      As String
     Dim val2replace As String
         
     RetStr = myString
         
     Set objRegExp = CreateObject("VBScript.RegExp")
         
     objRegExp.Pattern = "\s\d*\.\d*\s"
     objRegExp.Global = True
      
     If objRegExp.test(myString) Then
         Set colMatches = objRegExp.Execute(myString)
              
         For Each objMatch In colMatches
             val2replace = Replace(objMatch.Value, ".", ",")
             RetStr = Replace(RetStr, objMatch.Value, val2replace)
         Next
     End If
         
     ЗАМЕНАТОЧКИ = RetStr
End Function

Function ZamTo(ss)
Dim n_, i, a_, jj, aa_
      On Error Resume Next
      n_ = Len(ss)
      For i = 1 To n_ Step 3
          a_ = Mid(ss, i, 3)
          jj = WorksheetFunction.Find(".", a_)
          If Err.Number = 0 Then
              aa_ = Replace(a_, ".", ",")
              If IsNumeric(aa_) Then
                  ss = Replace(ss, a_, aa_)
              End If
          End If
          Err.Clear
      Next i
      ZamTo = ss
      On Error GoTo 0
End Function