For servers that don't offer SSI support, use the fakessi.pl Perl program to emulate SSI behavior. (The program is at http://sw.cse.bris.ac.uk/WebTools/fakessi.html.)
To use fakessi.pl with the CERN server, specify that the server executes the program whenever a client requests a file ending in .shtml:
Exec /*.shtml /usr/local/etc/httpd/cgi-bin/fakessi.pl
(assuming that usr/local/etc/httpd/cgi-bin is the proper directory).