An important fact: you can assign an advanced code from a different device code:
"P" [two blinks], "994" [two blinks], "advanced code device", "p" , "three digit advanced code," "device assigned to", "assigned key".
and the "assigned key" could actually be: "P", "assigned shifted key"
If your components are really new, you might have no choice but to build new device codes through JP1. There's always a chance that some JP1er learned all the commands you need and decoded them and the devices providing the commands are built in to the remote. If you didn't find what you need in the advanced codes at hifi-remote.com, you might be out of luck.
Minis and combos can be a real pain. Depending on the brand, you often have to use one device code for the DVD and another for the VHS and another for the Tuner.... and when you're committed to using a 5-in-1, you run out of devices real quick. this is one of the classic gotchas of universal remotes. Learning helps, but you only get so many bytes of learning space.
at this point you either:
a) buy a better remote ($20 buys a lot these days)
or
b) learn to solder (JP1 - don't get me started on the 2103!)