Colocar em Maiúsculas as Primeiras Letras de Todas as Palavras (Capitalize) - VBA

Function Captalize(X)

Dim Temp$, C$, OldC$, i As Integer

If IsNull(X) Then
Exit Function
Else
Let Temp$ = CStr(LCase(X))

Let OldC$ = " "
For i = 1 To Len(Temp$)
Let C$ = Mid$(Temp$, i, 1)
If C$ >= "a" And C$ <= "z" And (OldC$ < "a" Or OldC$ > "z") Then
Mid$(Temp$, i, 1) = UCase$(C$)
End If
Let OldC$ = C$
Next i
Let Proper = Temp$
End If
End Function