After a lot of searching... I think this maybe what you are after.

[Link: remotecentral.com]

and

[Link: avsforum.com]


Closed Captions on/off
0x2B
Device Code: 0 Function: 43
0000 006C 0012 0002 0153 00A9 0013 00A9 0013 00A9 0013 0054 0013 00A9 0013 0054 0013 00A9 0013 0054 0013 0054 0013 0054 0013 0054 0013 0054 0013 0054 0013 00A9 0013 00A9 0013 0054 0013 0054 0013 0468 0153 0054 0013 0D13

Hope that helps!

Cheers
Jason