In Order to remote control a TH-85XV200W http://www.panasonic.com/business/plasma/plasmas.asp you need to know 2 things:
a) the LAN Port only works if you set the remote from RS232 to LAN
b) you need to LOG into the webinterface (L:user1 P:Panasonic) and change the Password to "" (no password)
Now you can create a TCP Connection and send Commands to the Display.
Example
Power ON:
TCPSEND1,[h02]PON[h03][CR]
All command start with STX [h02] and end with ETX [h03] followed by a [CR]
Have fun, I hope this is helpfull
Daniel