As far as I can see that model does not have a built in 'TV Out' facility, so the only way to get an external display would be to a computer monitor using the VGA out socket, or you can get cables which connect the VGA out on the lappy to s-video or composite on the TV.
but you will have to have a separate lead for the sound.
- not sure if you really mean RS232 port on the TV? That is quite an old connector used for e.g. serial devices such as mice, before PS2 connectors or USB.