Sub RUS_Chr()
  Dim LATChr$: LATChr = "CcEeTOopPAaHKkXxBM06"
  Dim RUSChr$: RUSChr = "СсЕеТОорРАаНКкХхВМОб"
  Dim i%, iCell As Range
  Dim k As Integer
   k = 0
      For Each iCell In ActiveSheet.Range("A1")
        For i = 1 To Len(RUSChr)
        With iCell
           If .Value Like "*" & Mid(RUSChr, i, 1) & "*" Then
           k = k + 1
           End If
        End With
        Next i
      Next iCell
   Cells(10, 1) = k
   End Sub

Sub RUS_Chr()   
  Dim LATChr$: LATChr = "CcEeTOopPAaHKkXxBM"   
  Dim RUSChr$: RUSChr = "СсЕеТОорРАаНКкХхВМ"   
  Dim i%, iSht As Worksheet   
  For Each iSht In ThisWorkbook.Sheets   
     For i = 1 To Len(LATChr)   
        iSht.UsedRange.Replace _   
              What:=Mid(LATChr, i, 1), _   
              Replacement:=Mid(RUSChr, i, 1), _   
              LookAt:=xlPart, _   
              SearchOrder:=xlByRows, MatchCase:=True   
     Next i   
  Next iSht   
End Sub