passing Windows NT user name to postgres triggers for logging

Hi,

we are currently using the following configuration:
There is a postgresql database running on linux. User applications are
running on Windows NT, using Access as a frontend. The tables are
connected as static ODBC links with username and password in their DSN
definitions.

This means: Many different users may connect to our application server
with different NT user accounts. But within the scope of the postgres
database there is only one user. This is the user the ODBC connections
are defined with.

Our problem:

When implementing logging functions/triggers in postgresql, we have only
the pg username (getpgusername()), but we need the NT user name of the
users that connect to our terminal server and open our access frontend.

My questions:

Is there any trick to get the NT user names passed through the
connection or SQL statement?

For example, if we decide to let every user get its own postgres
account, there would still be the problem that one has to define one
single username when linking the ODBC data source into access.

Are there any other solutions?

We simple need to get the users name in our triggers.

Thank you a lot,

Markus