Function uuu$(t$)
 With CreateObject("VBScript.RegExp"): .Pattern = "[а-яё]"
    uuu = .Execute(t)(0)
 End With
End Function

Sub FirstBuk()
Dim RE As Object
Dim objMatches As Object
Dim i As Long
  Set RE = CreateObject("VBScript.RegExp")
For i = 2 To Cells(Rows.Count, 2).End(xlUp).Row
  With RE
    .Global = True: .IgnoreCase = False: .MultiLine = False
    .Pattern = "[а-яё]"
    If .test(Cells(i, 2)) Then
      Cells(i, 4) = .Execute(Cells(i, 2))(0)
      Set objMatches = .Execute(Cells(i, 2))
      Cells(i, 5) = objMatches.Item(0).firstindex + 1
    End If
  End With
Next
End Sub