Congrats Shanakor for getting past 5 days! That is an accomplishment in itself for sure as those early days are very difficult at times and a real test of our quit smoking commitment :)
It is good to reward yourself as you reach milestones - that's for sure. It's hard work to quit and a little treat or some fun along the way is necessary. Having said that, be very careful with the drinking thing. I have read many a post where someone's quit as been lost due to over indulgence with alcohol. I can't lie to you here - it's a potentially dangerous situation particularly early on in your quit and I'm sure you'll have others telling you this as well.
That's the bad news. Now having said that, in that you are aware of these things, that is a good thing. You know you must be on your guard. I would try to limit the drinking your first time out in this kind of situation until you know how YOU will react to drinking while staying quit. Personally, it has not affected me at any point in my own quit to have a few drinks but I know it does affect some others negatively.
Speak with your friends maybe before the night gets going and express your concerns to them. They sound like they can maybe help watch over you to make sure you don't light up.
You want to feel like nothing is missing for that day? Sorry, that's not going to happen first time going through this situation as this quitting thing is a 24/7 deal and you will still need to be dealing with the quit symptoms and fighting the urge to smoke while you enjoy your night out with friends. You CAN do both you know if you take things in moderation. The good news is once you go through this experience successfully, you will know exactly how to handle these outings in future and pretty soon, you will feel very comfortable going out to party as a non-smoker. That's how quitting works. You face different situations as a non-smoker and your brain rewires itself to learn how to live life enjoyably as a non-smoker.
Be sure to report back in and let us know how things went :)