JP1 is pretty easy, but your URC-7200 would require a "medium to difficult" hardware modification to make it JP1-able. If your C6 is a URC-6200 then it's the same story for that, but if it's a URC-6800 then the mod is really easy (it's just needs pins).
Also, the only way to be sure that you can create new codes using JP1 is if you have a learning remote, like the URC-7800 version of the C7. We do have a few Rotel files, but we don't have one for your exact model, so I can't guarantee if any of them will work. We have files for the following models: RSX-972, RA-985BX, RC-995 and RSX-1055.
As for using JP1, check out the following doc...
[Link: hifi-remote.com]