There are discrete codes here at RC for a Denon DVD made by Panasonic.
[Link: remotecentral.com]These are the discrete power codes for the Denon DVD-9000:
Device Code: 8 Function: 177-On
0000 006D 0000 0020 000A 001E 000A 001E 000A 001E 000A 0046 000A 001E 000A 0046 000A 001E 000A 001E 000A 001E 000A 0046 000A 0046 000A 001E 000A 0046 000A 001E 000A 001E 000A 0679 000A 001E 000A 001E 000A 001E 000A 0046 000A 001E 000A 001E 000A 0046 000A 0046 000A 0046 000A 001E 000A 001E 000A 0046 000A 001E 000A 0046 000A 0046 000A 0679
Device Code: 6 Function: 192-Off
0000 006D 0000 0020 000A 001E 000A 0046 000A 0046 000A 001E 000A 001E 000A 001E 000A 001E 000A 001E 000A 001E 000A 001E 000A 001E 000A 0046 000A 0046 000A 001E 000A 001E 000A 0679 000A 001E 000A 0046 000A 0046 000A 001E 000A 001E 000A 0046 000A 0046 000A 0046 000A 0046 000A 0046 000A 0046 000A 001E 000A 001E 000A 0046 000A 0046 000A 0679
If the On command acts as a toggle then it probably doesnt respond to discrete codes.
Most DVD's will turn On, when you select the Play button. So a macro for Play|Stop=On and Play|Power=Off
You may need to experiment with a slight delay between commands on certain remotes.
Please let me know if these work for you.
-Jon