EXCEL VBA: RICAVARE IL NOME UTENTE DI WINDOWS

Inserendo in un modulo VBA di excel il seguente codice, è possibile ricavare il nome utente di windows:

Public Declare Function GetUserName Lib "advapi32.dll" _
Alias "GetUserNameA" (ByVal lpBuffer As String, nSize As Long) As Long

Public Function ReturnUserName() As String
 ' returns the NT Domain User Name
 Dim rString As String * 255, sLen As Long, tString As String
    tString = ""
    On Error Resume Next
    sLen = GetUserName(rString, 255)
    sLen = InStr(1, rString, Chr(0))
    If sLen > 0 Then
        tString = Left(rString, sLen - 1)
    Else
        tString = rString
    End If
    On Error GoTo 0
    ReturnUserName = UCase(Trim(tString))
End Function