Hi Julia,
No, DIAdem doesn't support any commands like this. But you can use the Microsoft Windows Scripting Host. The current user is:
Dim objNet,name
Set objNet=CreateObject("WScript.Network")
name=objNet.UserDomain & "\" & objNet.UserName
msgbox name
For more info please refer to the Scripting Host help on the MS web page.
Greetings
Walter