I'm not sure ... this would depend on many different things. There are plenty of variables available (like the UserName, for example), but I'm not sure how those interact with your smartcard. Can you drop to the Command line (i.e. click Run, then enter "cmd")? If so, enter this:
set
and press the Enter key ... you'll see all the environment variables listed. You can refer to them in VBA like this:
Environ("TheNameOfTheVariable")
so on my machine, this:
Environ("UserName")
Returns "Scott"
I'm not sure, however, that your smartcard will reset these variables when a user "logs in" ... this may be the case however ...