There are a few ways to go about this but the best I have found:
Paste this into a new module:
Function fOSUserName() As String
On Error GoTo fOSUserName_Err
Dim lngLen As Long, lngX As Long
Dim strUserName As String
strUserName = String$(254, 0)
lngLen = 255
lngX = apiGetUserName(strUserName, lngLen)
If lngX <> 0 Then
fOSUserName = Left$(strUserName, lngLen - 1)
Else
fOSUserName = ""
End If
fOSUserName_Exit:
Exit Function
fOSUserName_Err:
MsgBox Error$
Resume fOSUserName_Exit
End Function
Then, use this where you want the log in name to be recorded:
=FOSUserName()