I add a TBS or two to my pulled pork rubs all the time...The flavor is good and the red color it adds is great.
Im a big fan of Butcher's BBQ rubs. He has a sampler pack you can order pretty cheap with all his rubs and you use each one to find the ones you like. go to his website and check them out. just google Butcher BBQ.
It is the zest of the fruit that you need. You can use a zester but I find a vegetable peeler works best as it comes off in wider strips and is therefore quicker.
Method 1 - Place the strips in an oven at about 50 C (120 F) until it is dry - or use a dehydrator if you have one. When dry place in a spice/coffee grinder and pulse until it resembles fresh ground pepper. Mix 1:1 with fresh ground black pepper and store in an airtight container
Method 2 - Place fresh lemon zest and whole peppercorns into a bowl with a squeeze of lemon juice. Allow to stand for about an hour. Strain off any excess lemon juice and place on a baking tray in the oven at 50 C (120 F) until dry. Blitz in a grinder until you have the texture you want.
Method 1 is quicker, however method 2 gives you a more intense flavour.
Once you have removed the zest then extract the juice from the fruit - which you can freeze and use in marinades in the future.
Sorry I read it that you were trying to make orange pepper for a rub. Yes you will need to add salt and sugar to make it into a rub itself. If you make the orange pepper and store it as a spice in an air tight container you can use it in any recipe in place of lemon pepper - or even black pepper to add an extra citrus layer.