I apologize for not making myself clear. The Sony changer command string is a disk load command followed by the slot number and terminated by a carriage return. These are sent to the changer as a continuous string of characters. Obviously I don't want to set up 400 seperate commands so there must be a way you can save the key presses of the numbers, edit them into the command, then send the whole string to the changer. Note, with RS-232, each command is a string of characters ended with a carriage return, it does not work like IR, where each key press is interpreted and processed as you go. I was thinking that perhaps the numbers are held in a variable in the MSC-400 and then the entire number is inserted in the command as a variable. It is also possible that I am completely wrong and there is a different technique for doing this. The programmer's guide doesn't give much help with "How to".
The remote I am planning on using is the MX-980, although it shouldn't matter since the RS-232 commands are issued by the MSC-400.