The peppercorns are not likely to absorb the flavour of the lemon rind. Lemon pepper is a combination of 2 herbs - peppercorns and lemon. Grind the peppercorns, then stir in the dried lemon rind. You can add some salt to taste if you want, but it's probably better (if you're going to be using salt) to add it separately to each dish - do the taste test before serving.
You don't need to use lemon rind, either. You can use any lemon-flavoured herb, such as lemon verbena, or lemon myrtle, or even lemon geranium (pelargonium). Each has a lemony flavour, but each is unique in its undertones. You might like to experiment with lemon thyme, or lemon savory, or lemongrass.
It's one reason I rarely use herb or spice blends. I prefer to keep things separate, so I can vary the amount of each that I add to dishes.