The power command you posted in Pronto Hex is the standard power command for TVs using the RC5 protocol.

Prontos have a condensed form for RC5 that looks like

5000 0000 0000 0001 00wx 00yz

Where you replace the wx with the "system number" (which is 0 for your TV and all similar TVs) and replace yz with the two digit hex code of the command (0C for power, etc.).

The condensed form gets something called the "toggle bit" inside the protocol correct, where the regualr Pronto Hex can't.

But I don't know whether your Xantech would understand the condensed form. If not, you can use the MakeHex program with the RC5.irp file to generate all your commands in ordinary Pronto Hex.