PROGRAMMING A LEARNED IR CODE TO A SHIFT KEY

Hello,

I'm pretty sure I've read this entire discussion and haven't found an answer to this question:

Can you program a learned key to a shift (P) operation? and if so how?

To be explicit I havr remote commands for which magic code do not exist and I want to program them into the 15-1994, but I don't want to put it on a normal key, I want them to be on a shift (P) key.

Thanks,

Jason