pattern for full session folder name in log file

Hello,
is there a pattern like !S to to have the "session folder name" in the logging dialog?

The my session are structured in a way like this:

group1/server1
group1/server2
group2/server1
group3/server2

It would be nice to have this structure present in the logging as well.
The log files would then look like:

log\group1_server1.log
log\group1_server2.log
log\group2_server1.log
log\group2_server2.log

I have not yet found any possibility to create log files like this but I would appreciate it very much.

Thanks,
Yor Feix

Session folder name is actually part of the session name, so !S resolves to group1-server1.log. Have you tried it?