Option Explicit

Public Sub REName_()

    Range_2_Proper ActiveSheet.UsedRange

End Sub

Public Sub Range_2_Proper(r As Range)

    Dim ceLL As Range

    For Each ceLL In r

        With ceLL

            .Value = a1_UPPER_2_Proper( _
                    Split(.Value))

        End With
    Next
End Sub

Public Function a1_UPPER_2_Proper(a1 As Variant) _
        As String

    Dim x As Long

    For x = LBound(a1) To UBound(a1)

        If a1(x) = UCase(a1(x)) Then

            a1(x) = WorksheetFunction.Proper(a1(x))

        End If

    Next

    a1_UPPER_2_Proper = Join(a1)

End Function

Sub tt()
    ar0 = Selection.Value
    For i = 1 To UBound(ar0)
        For j = 1 To UBound(ar0, 2)
            fl_ = 0
            ar = Split(ar0(i, j))
            For k = 0 To UBound(ar)
                If Not IsNumeric(Left(ar(k), 1)) Then
                    If Mid(ar(k), 2) <> LCase(Mid(ar(k), 2)) Then
                        If Left(ar(k), 1) = UCase(Left(ar(k), 1)) Then
                            ar(k) = Application.Proper(ar(k))
                            fl_ = 1
                        End If
                    End If
                End If
            Next k
            If fl_ Then
                ar0(i, j) = Join(ar)
            End If
        Next j
    Next i
    Selection = ar0
End Sub