Internet and intranet not accessing simultaneously

Dear Sir,
..
My organsation MTNL is having a MICN meaning MTNL integrated computer
Network Coonecting all the servers of delhi through routers. On this MICN
they have connected a server for MTNL INTRANET accessible with IE5 AND OE5
and above with IP address as 192.30.29.24 with name of site address as
www.mtnl.com. I am able to access this site when I am not connected to
intermet. I want to access internet and intranet simultaneously without
switching off internet and secondly I want to configure my OE in such a way
that new mails are watched evey minute on intranet while mails on internet
to be watched only when iternet is on. How to go ahead.
Regards
Arora SK