[syslog-ng]about syslog

[Moktar KONE]

hi ,
I have three machines A B and C which run syslog (not syslog-ng) and they
send now their logs toward a remote host S.
How is it possible with syslogd (running over S) to manage differents logs
from A, B and C according to the log source (i.e create a file for log
coming from A , an other file for log coming from B and an other file for
C).
the machine S, which receive logs is running syslogd , how can it manage the
logs coming from the others machines according to their source.
If syslog is not able to manage this , can syslog-ng do it?how?
thanks