If you declare the 11.70 instance in your 9.40 instance $INFORMIXDIR/etc/sqlhosts file, on the 9.40 host, you can access to the 11.70 instance as well as the 9.40, with the dbaccess utility.
Else, you can dowload the CSDK, giving access to ODBC and all.
You can also build Perl DBI module, same for Python, php etc...