When a command is held down it typically sends the header information first and the actual command is what is repeated. You can do this 2 ways in the MX900. One is to use the repeat command and give it a very high number like 999. I forget how many times it needs to repeat to equal one second. If the repeat command is in milliseconds then it would need 1000 repeats.
The other way to do this is to use a macro and the first command in the macro is the regular learned code or from the database and the following commands would be the learned command with the header removed. To do this put a book between the two remotes. Tell the 900 to learn and then press the button on the Denon's remote. Wait 1 second and then remove the book. That way it never sees the header information. You typically need 6 or more of the learned commands without the header for 2 seconds worth of codes.
